Battery explosion-proof structure, battery and battery pack

Abstract

The invention 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 the priority of the international application with the application number PCT / CN2023 / 143521 filed with the National Intellectual Property Administration on December 29, 2023. The entire content of the above application is incorporated herein by reference. Technical Field

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

[0003] An explosion-proof diaphragm is generally provided on the battery cover plate. The explosion-proof diaphragm gradually deforms until it explodes as the internal pressure increases. In related technologies, during the thermal runaway process of the battery, when the battery temperature rises to a certain stage, the internal electrolyte will decompose into combustible gases such as methane. As the battery temperature continues to rise, the battery will also decompose into combustion-supporting gases such as oxygen. When the internal pressure of the battery further increases, the explosion-proof diaphragm bursts. At the moment when the explosion-proof diaphragm bursts, the combustible gas, the combustion-supporting gas, and the battery internal substances interact with each other, intensifying the degree of thermal runaway and easily causing the battery to explode. Summary of the Invention

[0004] Embodiments of this application provide a battery explosion-proof structure, a battery, and a battery pack to solve the problem that when the explosion-proof structure in related technologies bursts, the interaction between the combustible gas, the combustion-supporting gas, and the battery internal substances intensifies the degree of thermal runaway and causes the battery to explode.

[0005] In a first aspect, an embodiment of this application provides a battery explosion-proof structure, including a cover plate. The cover plate is provided with a first notch and a second notch. The thickness of the cover plate at the first notch is less than the thickness of the cover plate at the second notch. The first notch includes a connected first section and a second section. The first section has a first end and a second end, and the second section has a third end and a fourth end. 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 this application provides a battery, including the battery explosion-proof structure described above;

[0007] A winding core;

[0008] A housing. The winding core is installed in the housing. One end of the housing is provided with an opening. The cover plate is hermetically connected to the housing to block the opening.

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

[0010] The battery explosion-proof structure, battery, and battery pack provided by the embodiments of the present application are provided. By setting a first notch and a second notch on the cover plate, the thickness of the cover plate at the position where the first notch is located is less than the thickness of the cover plate at the position where the second notch is located. The first notch includes a connected first section and a second section, and the distances between the two ends of the first section and the two ends of the second section are different, which is beneficial 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 opens first, and then the position of the second notch on the cover plate opens, forming a secondary pressure relief of the battery. The first opening can discharge combustible gases, and the second opening can discharge combustion-supporting gases, thereby achieving the purpose of discharging combustible gases and combustion-supporting gases at different times. It overcomes the problem that when the explosion-proof structure in the related technology explodes, due to the interaction of combustible gases, combustion-supporting gases, and battery internal substances, the degree of thermal runaway is aggravated, causing the battery to explode, improves the reliability of the cover plate, and ensures the explosion-proof effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present application. For those skilled in the art, without creative efforts, other drawings can also be obtained based on these drawings.

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

[0013] Figure 1 It 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 is Figure 1 the A-A cross-sectional view in

[0015] Figure 3 is Figure 1 the partial enlarged view at A in

[0016] Figure 4 is Figure 2 the partial enlarged view at B in

[0017] Figure 5 It is a top view of the second form of the battery explosion-proof structure provided by the embodiments of the present application.

[0018] Figure 6 is Figure 5 the B-B cross-sectional view in

[0019] Figure 7 It is a marked diagram of the first notch in the battery explosion-proof structure provided by the embodiments of the present application.

[0020] Figure 8 It is a top view of the third form of the battery explosion-proof structure provided by the embodiment of the present application.

[0021] Figure 9 It is Figure 8 the L-L sectional view in

[0022] Figure 10 It is Figure 8 the marking diagram of

[0023] Figure 11 It is a sectional view of the battery provided by the embodiment of the present application.

[0024] Figure 12 It is Figure 11 the partial enlarged view at the H position in

[0025] Figure 13 It is Figure 11 the partial enlarged view at the M position in

[0026] Figure 14 It is a perspective view of the battery pack provided by the embodiment of the present application.

[0027] Figure 15 It is a side view of the battery pack provided by the embodiment of the present application.

[0028] Figure 16 It is Figure 15 the D-D sectional view in

[0029] Explanation of reference numerals:

[0030] 100, battery; 110, cover plate; 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-part; 114, second sub-part; 1141, sunken platform; 1142, convex platform; 115, third sub-part; 116, fourth sub-part; 117, first side surface; 118, second side surface; 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, housing; 151, opening; 152, positive terminal; 153, flange; 154, pressing plate; 155, seal; 160, first current collector plate; 170, second current collector plate; 180, insulating part. Detailed implementation manners

[0031] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative efforts belong to the scope of protection of the present application.

[0032] Embodiments of the present application provide a battery explosion-proof structure, a battery, and a battery pack to solve the problem that when the explosion-proof structure in the related art explodes, the interaction of combustible gas, combustion-supporting gas, and the substances inside the battery exacerbates the degree of thermal runaway and causes the battery to explode. The following will be described in conjunction with the drawings.

[0033] See Figure 1 、 Figure 5 and Figure 8 As shown in

[0034] In some embodiments, the cover plate 110 has 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 using SPCC material, nickel can be plated on both surfaces of the cover plate 110, and the thickness of the plating layer is 0.3 μm to 8 μm, and the plating layer thickness on both 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 is opened first to discharge combustible substances, and then the position of the second notch 112 on the cover plate 110 is opened to discharge combustion-supporting substances. The first notch 111 includes a connected first section 1111 and a second section 1112. The first section 1111 has a first end 1113 and a second end 1114, and the second section 1112 has a third end 1115 and a fourth end 1116. On one side surface 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 beneficial 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 starts to open from the second end 1114 and the fourth end 1116 first, which is beneficial to the directional opening of the first notch 111. The cover plate 110 at the first notch 111 is opened under the first pressure, and the cover plate 110 at the second notch 112 is opened under the second pressure, and the first pressure is less than the second pressure. Both the first pressure and the second pressure refer to the pressure inside the battery. Thus, secondary pressure relief of the battery is formed. The first opening can discharge combustible gas, and the second opening can discharge combustion-supporting gas, so as to achieve the purpose of discharging combustible gas and combustion-supporting gas at different times, overcoming the problem that when the explosion-proof structure in the related art explodes, due to the interaction of combustible gas, combustion-supporting gas and the substances inside the battery, the degree of thermal runaway is aggravated and the battery explodes, and the explosion-proof effect is good.

[0037] In some embodiments, referring to Figure 1 As shown, along the radial direction of the cover plate 110, the first notch 111 and the second notch 112 are arranged at intervals, 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 plate 110 deforms and bulges into a hemispherical or hat shape. By setting the first notch 111 near the center of the cover plate 110, the deformation amount at the position of the first notch 111 is larger, which is beneficial to the opening of the first notch 111.

[0039] In some embodiments, referring to Figure 8 As shown, the second notch 112 is arc-shaped, 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. In some embodiments, along the circumferential direction of the second notch 112, the ends of the first notch 111 and the ends of the second notch 112 are arranged at intervals. The pressure relief area is large enough to ensure the pressure relief effect.

[0040] On the basis of the above embodiments, referring to Figure 8 As shown, the first notch 111 and the second notch 112 are connected, 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 enclose 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 plate 110 enclose a closed shape. While ensuring the pressure relief area, after the cover plate 110 at the position of the first notch 111 is opened, it breaks through the cover plate 110 at the position of the second notch 112 from the connection between the first notch 111 and the second notch 112, which is beneficial to the opening of the cover plate 110 at the position of the second notch 112, ensuring that the explosion-proof structure can be opened smoothly. Moreover, the part of the cover plate 110 inside the first notch 111 and the second notch 112 is completely separated from the part of the cover plate 110 outside the first notch 111 and the second notch 112, realizing the complete opening of the explosion-proof structure, with a large enough pressure relief area 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, etc., and the first notch 111 and the second notch 112 are arranged at intervals.

[0043] It can be understood that when the cover plate 110 at the position of the second notch 112 is opened, the cover plates 110 on both sides of the second notch 112 are completely separated, forming a large pressure relief port, ensuring that the explosion-proof structure can be opened smoothly, realizing the complete opening of the explosion-proof structure, and ensuring the pressure relief effect.

[0044] In some embodiments, referring to 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, and the fourth end 1116 is closer to the center of the cover plate 110 than the third end 1115. The first notch 111 protrudes towards 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 distances between the second end 1114 and the fourth end 1116 and the center of the cover plate 110 are less than the distances 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 in an inverted V shape, with the tip of the first notch 111 close to the center of the cover plate 110. When the cover plate 110 deforms under the action of 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 beneficial to the extension of the first notch 111 from the second end 1114 and the fourth end 1116 towards the first end 1113 and the third end 1115 side when the first notch 111 is opened, ensuring the smooth opening of the first notch 111 and being beneficial to one-time pressure relief.

[0047] In a variant, 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, and the first notch 111 protrudes towards the edge of the cover plate 110.

[0048] In some embodiments, referring to Figure 3 as shown, the first notch 111 further includes a third section 1117 disposed between the second end 1114 and the fourth end 1116, and the third section 1117 is smoothly connected to 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 position of the third section 1117 on the cover plate 110 is opened first, and then extends to the first section 1111 and the second section 1112 to rupture respectively, which is beneficial to the opening of the first notch 111 and ensures the smooth start of one-time pressure relief.

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

[0051] In a variant, the first section 1111, the second section 1112, and the third section 1117 can also be linear.

[0052] In the embodiments 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 directions of the first section 1111 and the second section 1112 are different from the bending direction of the third section 1117, ensuring that the first section 1111 and the second section 1112 are smoothly connected through the third section 1117, which is beneficial to the first notch 111 being opened first at the third section 1117, and the arc-shaped design can increase the length of the first notch 111 and the opening area, which is beneficial to one-time pressure relief.

[0053] In some embodiments, referring to Figure 5 and Figure 10 as shown, the outer diameter of the second notch 112 is E1, and 24 mm ≤ E1 ≤ 40 mm. For example, 30 mm ≤ E1 ≤ 35 mm. Among them, 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 unlisted values. Reasonably setting the position of the second notch 112 on the cover plate 110 forms a large enough pressure relief area to ensure the pressure relief effect.

[0054] In some embodiments, referring to Figure 7 as shown, an included angle β is formed between the chord corresponding to the arc of the first section 1111 and the chord corresponding to the arc of the second section 1112, where 30° ≤ β ≤ 150°. Such as β can take values of 30°, 40°, 50°, 60°, 70°, 80°, 90°, 100°, 110°, 120°, 130°, 140°, 150° or other unlisted values. The chord corresponding to the arc of the first section 1111 refers to the straight line where the chord corresponding to the inner arc of the first section 1111 is located, and the chord corresponding to the arc of the second section 1112 refers to the straight line where the chord corresponding to the inner arc of the second section 1112 is located. The angle design of the first section 1111 and the second section 1112 is reasonable. Within the range of the included angle β, a smooth transition connection between the first section 1111 and the second section 1112 is achieved. The better the smoothness between the first section 1111 and the second section 1112, the smoother the opening of the first notch 111, and the situation of jamming during the opening of the first notch 111 is avoided.

[0055] In some embodiments, referring to 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, where L1 = L2. The first section 1111 and the second section 1112 are symmetrically arranged. 1 mm ≤ L3 ≤ 3 mm. Among them, the value of L3 can be 1 mm, 2 mm, 3 mm or other unlisted values, and 4 mm ≤ L1 = L2 ≤ 8 mm. The values of L1 and L2 can be 4 mm, 5 mm, 6 mm, 7 mm, 8 mm 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 relieving pressure, it breaks through from the third section 1117 and extends to both sides. The first section 1111 and the second section 1112 are symmetrically arranged, so that the forces on both sides are the same and the opening speeds are the same, ensuring the reliability of a single pressure relief.

[0056] In some embodiments, referring to Figure 4As shown in the figure, 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, where 20μm ≤ H1 ≤ 115μm and 25μm ≤ H2 ≤ 135μm. For example, 45μm ≤ H1 ≤ 55μm and 80μm ≤ H2 ≤ 100μm. Among them, the value of H1 can be 20μm, 30μm, 40μm, 50μm, 60μm, 70μm, 80μm, 90μm, 100μm, 110μm, 115μm or other unlisted values. The value of H2 can be 25μm, 35μm, 45μm, 55μm, 65μm, 75μm, 85μm, 95μm, 105μm, 115μm, 125μm, 135μm or other unlisted values. It can be understood that H1 < H2.

[0057] It can be understood that the thicker the thickness of the cover plate 110 at the positions 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 positions 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 positions of the first notch 111 and the second notch 112 is relatively thin, the first notch 111 and the second notch 112 may open within the normal working range of the battery, affecting the performance of the battery. If the thickness of the cover plate 110 at the positions of the first notch 111 and the second notch 112 is relatively thick, the pressure required to open the first notch 111 and the second notch 112 is relatively large, resulting in a situation where the battery is prone to explosion. In the embodiments 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, which can meet the normal operation of the battery, achieve secondary pressure relief, and prevent the occurrence of battery explosion.

[0058] In some embodiments, 5μm ≤ H2 - H1 ≤ 20μm. Among them, the value of H2 - H1 can be 5μm, 10μm, 15μm, 20μm or other unlisted values. Setting the difference between H2 and H1 within a reasonable range ensures the reliability of primary pressure relief and secondary pressure relief.

[0059] In some embodiments, refer to Figure 4As shown, the thickness of the area on the cover plate 110 outside the first notch 111 and the second notch 112 is C, where 0.4 mm ≤ C ≤ 1.0 mm. Among them, the value of C can be 0.4 mm, 0.45 mm, 0.5 mm, 0.55 mm, 0.6 mm, 0.65 mm, 0.7 mm, 0.75 mm, 0.8 mm, 0.85 mm, 0.9 mm, 0.95 mm, 1.0 mm or other unlisted values. By reasonably setting the thickness of the cover plate 110, while ensuring the structural strength of the cover plate 110, the first notch 111 and the second notch 112 can be processed to achieve secondary pressure relief.

[0060] In some embodiments, referring to Figure 4 As shown, the notch widths of the first notch 111 and the second notch 112 are the same, both being a, where 0.6 mm ≤ a ≤ 1.5 mm. Among them, 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 unlisted values. By reasonably setting the notch widths of the first notch 111 and the second notch 112, it is avoided that the notch widths of the first notch 111 and the second notch 112 are too small, which is not conducive to processing and opening, and it is also avoided that the notch widths of the first notch 111 and the second notch 112 are too large, resulting in too large an area of the first notch 111 and the second notch 112, which affects the structural strength of the cover plate 110.

[0061] In some embodiments, referring to Figure 5 As shown, the cover plate 110 includes a first sub - part 113 and a second sub - part 114. The first sub - part 113 and the second sub - part 114 are adjacent. The first sub - part 113 is close to the edge of the cover plate 110. At least part of the surface of the second sub - part 114 facing the core 140 is higher than the surface of the first sub - part 113 facing the core 140. At least part of the surface of the second sub - part 114 away from the core 140 is higher than the surface of the first sub - part 113 away from the core 140. The first notch 111 and the second notch 112 are both provided on the second sub - part 114.

[0062] It can be understood that, referring to Figure 6As shown, the cover plate 110 includes a first side surface 117 and a second side surface 118. The first side surface 117 is the side of the cover plate 110 away from the core 140, and the second side surface 118 is the side of the cover plate 110 facing the core 140. Along the direction from the second side surface 118 to the first side surface 117, the second sub - part 114 is at least partially higher than the first sub - part 113, that is, the first side surface 117 of the second sub - part 114 is at least higher than the first side surface 117 of the first sub - part 113, and the second side surface 118 of the second sub - part 114 is at least higher than the second side surface 118 of the first sub - part 113. The cover plate 110 is designed as a concave - convex structure. When the pressure inside the battery increases, the cover plate 110 deforms into a hemispherical or hat - shaped form after deformation, increasing the space between the cover plate 110 and the end of the core, preventing the rapid increase in the air pressure inside the battery and avoiding the occurrence of battery explosion.

[0063] Based on the above - mentioned embodiment, referring to Figure 5 As shown, the cover plate 110 further includes a third sub - part 115. The first sub - part 113, the second sub - part 114, and the third sub - part 115 are integrally formed by stamping. Along the radial direction of the cover plate 110, the first sub - part 113, the second sub - part 114, and the third sub - part 115 are concentrically arranged in sequence. The first sub - part 113 and the second sub - part 114 are annular, and the third sub - part 115 is circular. The first sub - part 113 is close to the edge of the cover plate 110. Along the direction from the second side surface 118 to the first side surface 117, that is, the direction away from the battery, the second sub - part 114 is at least partially higher than the first sub - part 113, and the third sub - part 115 is higher than the first sub - part 113. The first notch 111 and the second notch 112 are concentric with the second sub - part 114.

[0064] It can be understood that when the air pressure inside the battery increases, the cover plate 110 bulges and deforms. By designing the heights of the second sub - part 114 and the third sub - part 115 to be higher than the height of the first sub - part 113, the cover plate 110 deforms into a hemispherical or hat - shaped form after deformation, increasing the space between the cover plate 110 and the end of the core, preventing the rapid increase in the air pressure inside the battery and avoiding the occurrence of battery explosion.

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

[0066] Setting the cover plate 110 as a structure in which the first sub - part 113, the second sub - part 114, the fourth sub - part 116, and the third sub - part 115 are connected in sequence can be formed by stamping, which is beneficial to the processing and forming of the cover plate 110.

[0067] Based on the above-described embodiments, 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 facing away from the core 140 is higher than the surface of the fourth sub-portion 116 facing 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 by disposing the first notch 111 and the second notch 112 on the second sub-portion 114, during the deformation process of the cover plate 110, the deformation forces of the first sub-portion 113 and the fourth sub-portion 116 act on the first notch 111 and the second notch 112, which is beneficial to the smooth opening of the first notch 111 and the second notch 112. The fourth sub-portion 116 is connected to the electrodes of the battery, and the cover plate 110 is charged. The electric potential between the cover plate 110 and the housing 150 is the same, there is no potential difference, reducing the risk of corrosion of the cover plate 110 and improving the reliability of the battery.

[0069] In some embodiments, referring to Figure 6 as shown, the distance in the thickness direction of the cover plate 110 between the first side surface 117 of the second sub-portion 114 and the first side surface 117 of the first sub-portion 113 is B, where 0.8C ≤ B ≤ 1.5C. Here, C is the thickness of the area on the cover plate 110 other than the first notch 111 and the second notch 112. For example, B can take values such as 0.8C, 0.9C, 1.0C, 1.1C, 1.2C, 1.3C, 1.4C, 1.5C or other values not listed.

[0070] In some embodiments, referring to Figure 8 as shown, the second sub-portion 114 includes a connected sunk platform 1141 and a boss 1142. The sunk platform 1141 and the boss 1142 enclose a closed ring. In the direction away from the core 140, the sunk platform 1141 and the first sub-portion 113 are at the same height. The first side surface 117 of the sunk platform 1141 and the first side surface 117 of the first sub-portion 113 are in the same horizontal plane, and the second side surface 118 of the sunk platform 1141 and the second side surface 118 of the first sub-portion 113 are in the same horizontal plane. The boss 1142 is higher than the sunk platform 1141 and the first sub-portion 113. The first notch 111 is at least partially disposed on the sunk platform 1141, and the second notch 112 is disposed on the boss 1142.

[0071] It can be understood that by forming a sink 1141 and a convex platform 1142 on the second sub-section 114, the first notch 111 is set on the sink 1141, and the second notch 112 is set on the convex platform 1142. When the gas pressure in the battery increases and the cover 110 is deformed, the first notch 111 at the position of the sink 1141 is subjected to the force of the deformation of the cover 110, thereby achieving directional opening at the position of the first notch 111, ensuring the orderly conduct of the secondary pressure relief. Among them, 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 is opened 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-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. In addition, the surface of the first sub-portion 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-portion 116 away from the winding core 140 are located at the same height, which facilitates 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. In addition, 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, which is conducive to the processing and molding of the cover plate 110.

[0074] In some embodiments, see Figure 9 As shown, the depth of the depression 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 depression 1141 refers to the vertical distance between the first side surface 117 of the boss 1142 and the first side surface 117 of the depression 1141.

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

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

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

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

[0079] Among them, D1 takes values of 4mm, 5mm, 6mm, 7mm, 8mm, 9mm, 10mm, 11mm, 12mm or other unlisted values, and α takes values of 100°, 110°, 120°, 130°, 140°, 150°, 160°, 170° or other unlisted values. Reasonably set the size of the sunk platform 1141 to ensure the effect of the directional opening of the battery explosion-proof structure.

[0080] In some embodiments, under the first pressure, the cover plate 110 at the first notch 111 opens, and under the second pressure, the cover plate 110 at the second notch 112 opens. 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.

[0081] Under the normal operating conditions of the battery, the internal pressure of the battery will reach 0.5Mpa. Generally, the internal pressure increases with temperature and electrolyte decomposition during a period before the battery touches thermal runaway. In order to let the combustible gas decomposed from the electrolyte escape without affecting the normal operation of the battery, the first pressure P1 is set in (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 stage of battery thermal runaway, the battery pressure rises to a certain level and the explosion-proof valve needs to open and release the internal combustion substances of the battery to avoid the occurrence of 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, 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, semi-circular, trapezoidal, U-shaped or parabolic. The cross-sectional shapes of the first notch 111 and the second notch 112 on the cover plate 110 are the same or different, and the cross-sectional shapes are diverse, which is convenient for 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] where Q is the tensile strength of the material for preparing the cover plate 110;

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

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

[0088] By using the above formula (1) to calculate the thickness H2 of the cover plate 110 at the second notch 112, the second notch 112 is designed according to different positions and material properties, and then the thickness H1 of the cover plate 110 at the first notch 111 is designed according to the second notch 112, which is convenient for design, the calculation result is accurate, and the performance of the cover plate 110 is guaranteed.

[0089] In some embodiments, as shown in Figure 6 the cover plate 110 includes a first side surface 117 and a second side surface 118 which are oppositely arranged, and both the first notch 111 and the second notch 112 are arranged on the first side surface 117;

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

[0091] or, the cover plate 110 includes a first side surface 117 and a second side surface 118 which are oppositely arranged, the first notch 111 is arranged on the first side surface 117, and the second notch 112 is arranged on the second side surface 118;

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

[0093] It can be understood that the positions of the first notch 111 and the second notch 112 on the cover plate 110 are diverse, as long as the purpose of primary pressure relief and secondary pressure relief can be achieved. The diverse design facilitates the processing and forming of the first notch 111 and the second notch 112.

[0094] See Figure 11 、 Figure 12 and Figure 13 As shown, the embodiment of the present application further provides a battery, which includes 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. One end of the housing 150 is provided with an opening 151, and a cover plate 110 is hermetically connected 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 embodiments, and will not be elaborated here.

[0095] On the basis of the above embodiments, see Figure 12 and Figure 13 As shown, the battery further includes a first current collector plate 160, a second current collector plate 170, and an insulating member 180. The winding core 140, the first current collector plate 160, and the second current collector plate 170 are all arranged in the housing 150. The cover plate 110 is hermetically connected to the housing 150 and blocks the opening 151. The second side surface 118 of the cover plate 110 abuts against one side surface of the first current collector plate 160. The other side surface of the first current collector plate 160 is welded to the negative extreme end of the winding core 140. The edge of the first current collector plate 160 is connected to the inner surface of the housing 150, so that the cover plate 110 and the housing 150 are charged, and there is no potential difference between the cover plate 110 and the housing 150, reducing the risk of corrosion of the cover plate 110 and improving the reliability of the battery. A positive terminal 152 is provided at one end of the housing 150 away from the cover plate 110. The positive terminal 152 is hermetically connected to the housing 150 through an insulating sealing ring. The second current collector plate 170 is welded to the winding core 140 and the positive terminal 152 and is arranged between the positive extreme end of the winding core 140 and the positive terminal 152. In addition, an insulating member 180 is provided between the second current collector plate 170 and the end of the housing 150 to insulate the second current collector plate 170 and the housing 150.

[0096] In some embodiments, see Figure 12 As shown, the cover plate 110 and the housing 150 are hermetically connected through a sealing member 155, which is convenient for assembling the cover plate 110 and the housing 150, and the process is simple. The edge of the first current collector plate 160 is connected to the inner wall of the housing 150, so that the housing 150 is negatively charged. The first current collector plate 160 and the cover plate 110 may or may not be in contact. When the first current collector plate 160 is in contact with the cover plate 110, the cover plate 110 is also negatively charged, and there is no potential difference between the cover plate 110 and the housing 150, reducing the risk of corrosion of the cover plate 110 and improving the reliability of the battery.

[0097] On the basis of the above embodiments, see Figure 12As shown, a part of the side wall of the housing 150 near the opening 151 contracts inward to form a flange 153. The side wall of the opening 151 of the housing 150 is curled to form a pressing plate 154. The pressing plate 154 is arranged at a relative interval with the flange 153. The cover plate 110 is installed between the flange 153 and the pressing plate 154. A seal 155 is provided between the cover plate 110 and the flange 153 and the pressing plate 154 to ensure the sealing of the battery. Specifically, the seal 155 is an O-ring, and the compression rate of the O-ring is between 30% and 70% to improve the sealing effect.

[0098] In other embodiments, the cover plate 110 and the housing 150 are connected by laser welding. The laser welding process is simple and has good sealing performance. At this time, the first current collector plate 160 is in direct contact with the housing 150 so that the housing 150 is 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 elaborated here.

[0100] In some embodiments, referring to Figure 14 、 Figure 15 and Figure 16 As shown, the battery pack further includes a mounting base 130. The mounting base 130 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 by one. One end of the battery 100 close to the cover plate 110 is installed in the mounting groove 131. The baffle 132 is located on the side of the mounting groove 131 away from the battery 100. The first 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. The projection of the baffle 132 on one side surface of the cover plate 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. Among them, the baffle 132 can be a flat plate or an arc-shaped plate.

[0102] It can be understood that as the pressure inside the battery 100 increases, the first notch 111 in the sunk platform 1141 opens, and the gas and substances inside the battery 100 are ejected from the side of the first notch 111. By providing the baffle 132 on the mounting base 130, the baffle 132 is located below the sunk platform 1141, and the projection of the baffle 132 on the plane where the cover plate 110 is located is arranged in alignment with the first notch 111. The baffle 132 blocks the substances ejected from the battery 100 to avoid the situation that the ejected substances enter the adjacent battery 100 and contaminate the adjacent battery 100.

[0103] Referring to 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 better blocking effect.

[0104] On the basis of the above embodiment, refer to Figure 15 As shown in the figure, the mounting seat 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 arranged relatively spaced apart. The first sub-plate 133 is connected to the second sub-plate 134. The mounting groove 131 is opened on the first sub-plate 133. The baffle 132 is located between the first sub-plate 133 and the second sub-plate 134, and the baffle 132 is connected to the first sub-plate 133. The substances flowing out after the cover plate 110 is opened flow between the first sub-plate 133 and the second sub-plate 134, avoiding affecting other batteries.

[0105] The technical solutions and technical effects of the present application will be described in detail below through specific examples and comparative examples. The following examples are only partial examples of the present application and do not specifically limit the present application.

[0106] The first test group

[0107] In this test group, the structure of the battery explosion-proof structure is: refer to Figure 1 As shown in the figure, 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 circular. 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 the standard GB / T31485-2015.

[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 time difference between the opening of the first notch 111 and the second notch 112 is ΔT. Among them, T1 and T2 meet the following conditions: 50s ≤ T1 ≤ 100s, 60s ≤ T2 ≤ 150s, and the time 5s ≤ ΔT ≤ 50s.

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

[0111] Table 1.1: Parameters and verification results of the basic group 1

[0112]

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

[0114] Based on the parameters of basic group 1, the parameters of the cover plate 110 are controlled to change by the single-variable method to set the comparative examples and the examples. The variable parameter tables and verification results of the comparative examples and the examples are shown in Tables 1.2 to 1.8.

[0115] Table 1.2: Verification results of comparative examples and examples set by changing H1 and changing H2 accordingly based on basic group 1

[0116] H1 / μm H2 / μm Verification result 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, while meeting the performance of the explosion-proof structure, secondary pressure relief is achieved. When H1 is lower than the set range, the opening times of the first-stage pressure relief and the second-stage pressure relief are both earlier. When H1 exceeds the set range, the time interval between the two pressure reliefs is shorter, and the pressure relief effect of the explosion-proof structure is not good.

[0118] Table 1.3: Verification results of comparative examples and examples set by changing H2 to change H2 - H1 based on the parameters of basic group 1

[0119]

[0120]

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

[0122] Table 1.4: Verification results of comparative examples and examples set by changing L3 based on the parameters of basic group 1

[0123] L3 / mm Verification result 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, while meeting the performance of the explosion-proof structure, secondary pressure relief is achieved. 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 set by changing L1 and L2 based on the parameters of basic group 1

[0126] L1 and L2 / mm Verification result 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] As can be seen from Table 1.5, when L1 and L2 are within the set range, while meeting the performance of the explosion-proof structure, secondary pressure relief is achieved. When L1 and L2 are lower than the set range, the time interval between the two pressure reliefs is 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 the parameter of basic group 1 and different β settings

[0129] β Verification result 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] As can be seen from Table 1.6, when β is within the set range, while meeting the performance of the explosion-proof structure, secondary pressure relief is achieved. When β is lower than the set range, the time interval between the two pressure reliefs is 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] The second test group

[0132] In this test group, the battery explosion-proof structure is as follows: Refer to Figure 5 As shown, a first notch 111 and a second notch 112 are provided on the first side 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 circular. 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 sub-part 113 and a second sub-part 114, and both the first notch 111 and the second notch 112 are provided on the second sub-part 114.

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

[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. Among them, T1 and T2 meet the following conditions: 50s ≤ T1 ≤ 100s, 60s ≤ T2 ≤ 150s, 5s ≤ ΔT ≤ 50s.

[0135] The parameters related to the cover plate 110 include: H1, H2, H2 - H1, a, C, L1, L2, L3, β, B, E1. Set the basic group 2, and the parameters and verification results of the 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 times of the first notch 111 and the second notch 112 both meet the evaluation criteria. While meeting the performance of the explosion-proof structure, secondary pressure relief is achieved.

[0139] Based on the parameters of basic group 2, the parameters of the cover plate 110 are controlled to change by the single variable method to set the comparative examples and embodiments. The changed parameters and verification results of the comparative examples and embodiments are shown in Table 2.2.

[0140] Table 2.2: Verification results of comparative examples and embodiments with parameter B changed based on the parameters of basic group 2

[0141] B / mm Verification result 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 relieves is shorter. When B exceeds the set range, the time interval between the two pressure relieves is longer, and the effect of secondary pressure relief of the explosion-proof structure is reduced.

[0143] The third test group

[0144] The battery explosion-proof structure in this test group is: Refer to Figure 8As shown in the figure, the cover plate 110 includes a first side surface 117 and a second side surface 118 which are oppositely arranged. The first notch 111 and the second notch 112 are both arranged on the first side surface 117. The projections of the first notch 111 and the second notch 112 on one side surface of the cover plate 110 enclose a closed shape, that is, the first notch 111 and the second notch 112 are connected end to end and the first notch 111 and the second notch 112 are communicated. The cover plate 110 includes a first sub - part 113 and a second sub - part 114. The first sub - part 113 is adjacent to the second sub - part 114. The first sub - part is close to the edge of the cover plate 110. In the direction from the second side surface 118 to the first side surface 117, at least part of the second sub - part 114 is higher than the first sub - part 113. The first notch 111 and the second notch 112 are arranged on the second sub - part 114. The second sub - part 114 is provided with a connected sunken platform 1141 and a convex platform 1142. The sunken platform 1141 and the convex platform 1142 enclose a closed ring shape. The first side surface 117 of the sunken platform 1141 and the first side surface 117 of the first sub - part 113 are in the same horizontal plane. The second side surface 118 of the sunken platform 1141 and the second side surface 118 of the first sub - part 113 are in the same horizontal plane. The surface of the convex platform 1142 facing the core 140 is higher than the surface of the first sub - part 113 facing the core 140 and the surface of the sunken platform 1141 facing the core 140. The surface of the convex platform 1142 away from the core 140 is higher than the surface of the first sub - part 113 away from the core 140 and the surface of the sunken platform 1141 away from the core 140. At least part of the first notch 111 is arranged on the sunken platform 1141, and the second notch 112 is arranged on the convex platform 1142.

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

[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. Among them, 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 the basic group 3. The parameters and verification results of the basic group 3 are as shown in Table 3.1 below.

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

[0150]

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

[0152] Based on the parameters of basic group 3, the parameters of the cover plate 110 are controlled by the single-variable method to set the comparative examples and the embodiments. The variable parameters and verification results of the comparative examples and the embodiments are shown in Table 3.2.

[0153] Table 3.2: Verification results of comparative examples and embodiments set by changing D1 and D2 changing with D1 based on basic group 3

[0154] D1 / mm D2 / mm Verification result 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 relieves is longer. When D1 exceeds the set range, the time interval between the two pressure relieves is shorter, and the effect of secondary pressure relief of the explosion-proof structure is reduced.

[0156] In the above embodiments, the descriptions of the respective embodiments have their own emphases. For the parts not detailed in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0157] In the description of the present application, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more features.

[0158] The above has introduced in detail the battery explosion-proof structure and the battery provided by the embodiments of the present application. Specific examples are used herein to elaborate on the principle and implementation manner of the present application. The description of the above embodiments is only used to help understand the method and its core idea of the present application; at the same time, for those skilled in the art, based on the idea of the present application, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation to the present application.

Claims

1. A battery explosion-proof structure, characterized in that: The invention comprises a cover plate (110), wherein a first notch (111) and a second notch (112) are provided on the cover plate (110), 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), the first notch (111) comprises a first section (1111) and a second section (1112) connected to each other, the first section (1111) having a first end (1113) and a second end (1114), the second section (1112) having a third end (1115) and a fourth end (1116), and the distance between the first end (1113) and the third end (1115) is greater than the distance between the second end (1114) and the fourth end (1116).

2. The battery explosion-proof structure according to claim 1, characterized in that: The first notch (111) and the second notch (112) are arranged at intervals, 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), wherein the third section (1117) 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 used to make the cover plate (110); 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 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) comprises 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 a surface of the first sub-portion (113) facing the winding core (140), at least a portion of the surface of the second sub-portion (114) away from the winding core (140) is higher than a surface of the first sub-portion (113) away from the winding core (140), and the 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-portion (114) includes a boss (1142) and a sink (1141); the surface of the boss (1142) facing the winding core (140) is higher than the surface of the first sub-portion (113) facing the winding core (140) and 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 first sub-portion (113) away from the winding core (140) and the surface of the sink (1141) away from the winding 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 comprises a third sub-section (115), the second sub-section (114) being located between the first sub-section (113) and the third sub-section (115), the third sub-section (115) being circular, the third sub-section (115) being concentrically arranged with the second sub-section (114), and the sink (1141) and the boss (1142) forming a closed ring.

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

21. The 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; Or, the surface of the first sub-portion (113) facing the winding core (140), the surface of the sink (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 depression (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>2mm; α is the angle formed between the bottom and the side of the sink (1141), 100°≤α≤170°; C is the thickness of the area outside the 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) which 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) 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 second side surface (118); Alternatively, the cover plate (110) comprises 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) comprises 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); A shell (150), the winding core (140) is installed in the shell (150), one end of the shell (150) is provided with an opening (151), and the cover plate (110) is sealedly connected to the shell (150) to block the opening (151).

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); an 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 shell (150) are laser welded; Alternatively, the cover plate (110) and the housing (150) are sealedly 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, characterized in that: Also includes: The mounting seat (130) is provided with a plurality of mounting grooves (131) and a plurality of baffles (132); one end of the battery close to the cover plate (110) is mounted in the mounting groove (131); the baffle (132) is located on a side of the mounting groove (131) away from the battery; the first 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) 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 relatively spaced apart, the mounting groove (131) is provided on the first sub-plate (133), the baffle plate (132) is located between the first sub-plate (133) and the second sub-plate (134), and the baffle plate (132) is connected to the first sub-plate (133).

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