Single battery, battery pack and electric equipment

Abstract

The invention discloses a single battery, a battery pack and electric equipment, and belongs to the technical field of batteries, and the single battery comprises a shell which is provided with a containing cavity and a through hole communicated with the containing cavity. By arranging the convex part and the concave part of which the surfaces are of arc-shaped structures, the external force can be effectively transmitted to the foundation or the supporting structure and can be matched with the foundation or the supporting structure. Meanwhile, when the protruding part is subjected to large acting force opposite to the protruding direction of the protruding part, the protruding part can deform to a certain degree, so that the protruding part of the protruding part is reduced and converted into the concave part, and when the concave part is subjected to large acting force opposite to the concave direction of the concave part, the anti-explosion valve is protected. When the anti-explosion valve is used, the concave part can be deformed to a certain degree, so that the concave part of the concave part is reduced, the concave part is converted into the convex part, the change of the structure can also play a certain buffering role on the anti-explosion valve, the convex part is prevented from being damaged due to large acting force, and the safety of the anti-explosion valve is improved.

Description

Technical Field

[0001] The present application belongs to the field of battery technology, and in particular relates to a single cell, a battery pack and an electrical device. Background Art

[0002] The main function of the explosion-proof valve on the battery is to release pressure and exhaust gas. It is used to release the internal high-temperature and high-pressure gas in a directional manner when the battery experiences thermal runaway due to mechanical impact, internal abnormal lap short circuit, etc., thereby improving the safety performance of the battery pack. However, since the explosion-proof valve is in contact with the external environment, its structural strength is relatively low. Under the influence of external forces, the explosion-proof valve has a high risk of abnormal cracking and premature valve opening. Summary of the invention

[0003] Purpose of the invention: An embodiment of the present application provides a single cell battery, aiming to overcome the technical problem that the explosion-proof valve is subjected to external forces and has a high risk of abnormal cracking and premature valve opening; another purpose of the embodiment of the present application is to provide a battery pack; the third purpose of the embodiment of the present application is to provide an electrical device.

[0004] Technical solution: A single cell battery according to an embodiment of the present application includes:

[0005] A shell having a receiving cavity and a through hole communicating with the receiving cavity;

[0006] an explosion-proof valve connected to the housing and covering the through hole, the explosion-proof valve comprising a skirt portion, a protruding portion and a recessed portion, the protruding portion being arranged around the recessed portion and being connected to the recessed portion, the protruding portion being arranged to protrude along a first direction, the recessed direction of the recessed portion being opposite to the protruding direction of the protruding portion, the skirt portion being arranged around the protruding portion and being connected to the protruding portion, and a notch being arranged at the connection between the protruding portion and the skirt portion;

[0007] The single cell battery satisfies: 0.43≤C / B≤0.78;

[0008] The plane where the bottom of the skirt portion is located is the reference plane, B is the distance from the top of the protruding portion to the reference plane in the first direction, and C is the distance from the bottom of the recessed portion to the reference plane in the first direction.

[0009] In some embodiments, the protrusion is arranged to protrude away from the accommodating cavity, and the explosion-proof valve includes:

[0010] A first transition portion, wherein the first transition portion is disposed between the protruding portion and the recessed portion and surrounds the recessed portion, the protruding portion surrounds the first transition portion, the first transition portion includes a first side surface, the first side surface is disposed away from the accommodating cavity, the first side surface is a plane, and is perpendicular to the first direction.

[0011] In some embodiments, the first transition portion includes a second side surface, the second side surface is disposed opposite to the first side surface, and the second side surface is an arc surface.

[0012] In some embodiments, the first transition portion includes a third side surface, the third side surface is disposed opposite to the first side surface, the third side surface is a plane and is perpendicular to the first direction.

[0013] In some embodiments, the explosion-proof valve includes:

[0014] A second transition portion, the second transition portion surrounds the protruding portion, the protruding portion is connected to the skirt portion through the second transition portion, and the notch is disposed on the second transition portion;

[0015] The single cell satisfies: L1≥t1 and L1≥t2;

[0016] Wherein, L1 is the thickness of the second transition portion, t1 is the thickness of the protruding portion, and t2 is the thickness of the skirt portion.

[0017] In some embodiments, the single cell satisfies: 0.15mm≤t1 = t2≤0.2mm.

[0018] In some embodiments, the explosion-proof valve includes a connecting portion, the connecting portion surrounds the skirt portion, and the skirt portion is connected to the inner wall of the through hole through the connecting portion;

[0019] The single cell satisfies: 0.4mm≤D≤0.6mm;

[0020] Wherein, D is the thickness of the connecting portion in the first direction.

[0021] In some embodiments, the thickness of the housing is H, satisfying: 1mm≤H≤1.5mm.

[0022] A battery pack includes the single cell described in any one of the above.

[0023] An electrical device includes the single cell described in any one of the above, or includes the battery pack described in the above.

[0024] Beneficial effects: The single cell of the embodiment of the present application includes: a housing having a receiving cavity and a through hole communicating with the receiving cavity; an explosion-proof valve connected to the housing and covering the through hole. The explosion-proof valve includes a skirt portion, a protruding portion, and a recessed portion. The protruding portion surrounds the recessed portion and is connected to the recessed portion. The protruding portion protrudes in a first direction, and the recessed direction of the recessed portion is opposite to the protruding direction of the protruding portion. The skirt portion surrounds the protruding portion and is connected to the protruding portion. A notch is provided at the connection between the protruding portion and the skirt portion. The single cell satisfies: 0.43 ≤ C / B ≤ 0.78; wherein, the plane where the bottom of the skirt portion is located is used as a reference plane, B is the distance from the top of the protruding portion to the reference plane in the first direction, and C is the distance from the bottom of the recessed portion to the reference plane in the first direction. By providing the protruding portion and the recessed portion with arc-shaped structures on the surface, the external force can be effectively transmitted to the foundation or support structure, and the explosion-proof valve can be protected. At the same time, when the protruding portion is subjected to a large force in the direction opposite to its protruding direction, the protruding portion can be deformed to a certain extent, so that the protruding part of the protruding portion is reduced and transformed into a recessed part. When the recessed portion is subjected to a large force in the direction opposite to its recessed direction, the recessed portion can also be deformed to a certain extent, so that the recessed part of the recessed portion is reduced, and thus the recessed part is transformed into a protruding part. This structural change can also play a certain buffering role for the explosion-proof valve, avoiding damage to the protruding portion due to a large force, improving its safety, and reducing the risk of abnormal cracking and premature valve opening of the explosion-proof valve. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] 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 following drawings are only some embodiments of the present application. For those skilled in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0026] Figure 1 It is a three-dimensional view of the housing of the embodiment of the present application;

[0027] Figure 2 It is a sectional three-dimensional view of the housing of the embodiment of the present application;

[0028] Figure 3 It is a front sectional view of the housing of the embodiment of the present application;

[0029] Figure 4 For the embodiment of the present application Figure 3 The enlarged view of area A in;

[0030] Figure 5 It is a three-dimensional view of the explosion-proof valve of the embodiment of the present application;

[0031] Figure 6This is a front view cross-sectional view of the explosion-proof valve according to an embodiment of the present application. Among them, the second side surface on the first transition portion is an arc surface;

[0032] Figure 7 This is a front view cross-sectional view of the explosion-proof valve according to an embodiment of the present application. Among them, the second side surface on the first transition portion is a plane;

[0033] Figure 8 This is a front view cross-sectional view of the explosion-proof valve according to an embodiment of the present application. Among them, a second transition portion is provided on the explosion-proof valve;

[0034] Reference numerals: 10 - housing; 11 - accommodation cavity; 12 - through hole; 20 - explosion-proof valve; 21 - skirt portion; 22 - protruding portion; 23 - recessed portion; 24 - notch; 25 - first transition portion; 251 - first side surface; 252 - second side surface; 253 - third side surface; 26 - second transition portion; 27 - connecting portion; 30 - reference plane; X - first direction. Detailed implementation manners

[0035] 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 making creative efforts belong to the scope of protection of the present application.

[0036] In the description of the present application, it should be understood that 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. In the description of the present application, "a plurality" means two or more, and at least one means it can be one, two or more, unless otherwise clearly and specifically defined.

[0037] The main function of the explosion-proof valve on the battery is pressure relief and exhaust, which is used for the directional release of high-temperature and high-pressure gases inside the battery when thermal runaway occurs due to reasons such as mechanical impact and internal abnormal short circuit, thereby improving the safety performance of the battery pack. At present, the thickness of the single battery is gradually reduced during design, resulting in a gradual reduction in the size of the explosion-proof valve. How to reasonably set the structure of the explosion-proof valve within the limited length and width, so that its opening value meets the design requirements, while improving its structural strength, reducing the risk of abnormal cracking and premature opening when it is subjected to external forces, is a technical problem that needs to be solved at present.

[0038] In view of this, an embodiment of the present application provides a single battery to overcome at least one of the above technical problems.

[0039] Please refer to Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 and Figure 6 , in the embodiment of the present application, the single cell includes a housing 10 and an explosion-proof valve 20.

[0040] The housing 10 has a receiving cavity 11 and a through hole 12 communicating with the receiving cavity 11. The explosion-proof valve 20 is connected to the housing 10 and seals the through hole 12. The explosion-proof valve 20 includes a skirt portion 21, a protruding portion 22 and a recessed portion 23. The protruding portion 22 is disposed around the recessed portion 23 and connected to the recessed portion 23. The protruding portion 22 protrudes along the first direction X. The recessed direction of the recessed portion 23 is opposite to the protruding direction of the protruding portion 22. The skirt portion 21 is disposed around the protruding portion 22 and connected to the protruding portion 22. A notch 24 is provided at the connection between the protruding portion 22 and the skirt portion 21.

[0041] It can be understood that the explosion-proof valve 20 on the single cell is generally disposed on the battery cover plate. However, due to the current thinner battery design, the width of the cover plate connected to one side of the battery housing 10 is getting smaller and smaller. This results in the width dimension of the explosion-proof valve 20 originally disposed on the cover plate being restricted, and the explosion-proof valve 20 cannot be well disposed on the cover plate, which may cause the opening value of the explosion-proof valve 20 not to meet the design requirements of the battery. Therefore, in the present application, the explosion-proof valve 20 originally disposed on the battery cover plate is disposed on the battery housing 10 (such as Figure 1 ). The width of the upper housing 10 of the battery is generally greater than or equal to the width of the cover plate (at least a part of the cover plate needs to be embedded in the receiving cavity 11 of the housing 10, and at the same time, the space occupied by the cover plate is reduced, so the width of the cover plate is generally less than or equal to the width of the housing 10). The explosion-proof valve 20 can also be disposed on other sides of the housing 10. Disposing the explosion-proof valve 20 on the housing 10 can enable the housing 10 to provide a larger installation space for the explosion-proof valve 20, without restricting the width and length dimensions of the explosion-proof valve 20, meeting the design of the structural dimensions of the explosion-proof valve 20 and ensuring its normal valve opening.

[0042] Meanwhile, when the explosion-proof valve 20 is arranged on the housing 10 and its opening value meets the design requirements, a protruding portion 22 can be arranged on the explosion-proof valve 20, such that the protruding portion 22 protrudes along the first direction X (along the first direction, the protruding portion 22 protrudes from the skirt portion 21), and at least part of the surface of the protruding portion 22 is in an arc structure. When an external force in the direction opposite to the protruding direction of the protruding portion 22 acts on the protruding portion 22, the force acting on it is effectively transmitted to the foundation or the support structure through the protruding portion 22, that is, transmitted to the skirt portion 21, and the skirt portion 21 is connected to the housing 10, so as to transmit part of the acting force to the housing 10. Moreover, when the protruding portion 22 is subjected to a relatively large acting force in the direction opposite to its protruding direction, the protruding portion 22 can be deformed to a certain extent, such that the protruding part of the protruding portion 22 is reduced and transformed into a concave part (part of the protruding part of the protruding portion 22 can be transformed into a concave part, or can be completely transformed into a concave part). This structural change can play a certain buffering role for the explosion-proof valve 20, avoid damage to the protruding portion 22 due to a relatively large acting force, and improve its safety. A concave portion 23 is also arranged on the explosion-proof valve 20, and the protruding portion 22 is arranged around the concave portion 23. At least part of the surface of the concave portion 23 is in an arc structure, and the concave direction of the concave portion 23 is opposite to the protruding direction of the protruding portion 22. When an external force in the direction opposite to the concave direction of the concave portion 23 acts on the concave portion 23, the force acting on it is effectively transmitted to the foundation or the support structure through the concave portion 23, that is, transmitted to the protruding portion 22, and the protruding portion 22 is connected to the housing 10 through the skirt portion 21, so as to transmit part of the acting force to the housing 10. Moreover, when the concave portion 23 is subjected to a relatively large acting force in the direction opposite to its concave direction, the concave portion 23 can also be deformed to a certain extent, such that the concave part of the concave portion 23 is reduced, so that the concave part is transformed into a protruding part (part of the concave part of the concave portion 23 can be transformed into a protruding part, or can be completely transformed into a protruding part). This change in the structure can also play a certain buffering role for the explosion-proof valve 20, avoid damage to the concave portion 23 due to a relatively large acting force, and improve its safety.

[0043] The single cell satisfies: 0.43 ≤ C / B ≤ 0.78; wherein, the plane where the bottom of the skirt portion 21 is located is the reference plane 30, B is the distance from the top of the protruding portion 22 to the reference plane 30 in the first direction X, and C is the distance from the bottom of the concave portion 23 to the reference plane 30 in the first direction X. It can be understood that the ratio of the distance from the bottom of the concave portion 23 to the reference plane 30 in the first direction X to the distance from the top of the protruding portion 22 to the reference plane 30 in the first direction X is within the range of 0.43 to 0.78 (such as Figure 6),including 0.43 and 0.78, the value of C / B can be any value among 0.43, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.78 or the range value between any two values. When within this range and meeting the preset valve opening value of the explosion-proof valve 20, the compressive resistance of the protrusion 22 and the recess 23 can be effectively improved, and to a certain extent, the structural strength of the protrusion 22 and the recess 23 can be ensured (the protrusion 22 and the recess 23 constitute the main part of the explosion-proof valve 20. Improving the structural strength of the protrusion 22 and the recess 23 can also improve the structural strength of the explosion-proof valve 20), preventing the protrusion 22 and the recess 23 from being easily damaged or the valve opening in advance when being extruded by external forces. The values of C and B can be measured by a caliper or a 3D scanner. It should be noted that when testing the explosion-proof valve 20 in the embodiments of the present application, multiple groups of batteries installed with the explosion-proof valve 20 are taken for testing (the C / B ratios on each group of explosion-proof valves 20 are different), and a force of 0.4 Mpa can be applied to the explosion-proof valve 20 along the first direction X to observe whether the protrusion 22 and the recess 23 are cracked. The test results of the embodiments and the comparative examples are as follows in the table:

[0044]

[0045]

[0046] As can be seen from the above table, when a certain force is applied to the protruding portion 22 and the recessed portion 23 in the first direction X, when the value of C / B is in the range of 0.43 to 0.78 (including 0.43 and 0.78), the protruding portion 22 and the recessed portion 23 do not show a rupture phenomenon, indicating that the protruding portion 22 and the recessed portion 23 in this case have good compressive resistance and can reduce the risk of abnormal cracking and premature valve opening of the explosion-proof valve 20. When the value of C / B is less than 0.43, at least one of the protruding portion 22 and the recessed portion 23 ruptures. This situation may be due to the relatively large recess degree of the recessed portion 23 (that is, the C value is small), which causes the curvature of the arched structure formed by the recessed portion 23 to be too large (curvature refers to the measure of the bending degree of a geometric body), and also reduces its stability and compressive resistance. When a force is applied, a rupture phenomenon may occur; or it may also be due to the relatively large protruding degree of the protruding portion 22 (that is, the D value is large), which causes the curvature of the arched structure formed by the protruding portion 22 to be too large, resulting in a reduction in its stability and compressive resistance. When a force is applied, a rupture phenomenon may occur. When the value of C / B is greater than 0.78, at least one of the protruding portion 22 and the recessed portion 23 ruptures. This situation may be due to the relatively small recess degree of the recessed portion 23 (that is, the C value is large), which causes the curvature of the arched structure formed by the recessed portion 23 to be too small. The too small curvature will reduce the support effect of the structure and the compressive resistance. When a force is applied, a rupture phenomenon may occur; or it may also be due to the relatively small protruding degree of the protruding portion 22 (that is, the D value is small), which causes the curvature of the arched structure formed by the protruding portion 22 to be too small. The too small curvature will reduce the support effect of the protruding portion 22 and the compressive resistance. When a force is applied, a rupture phenomenon may occur.

[0047] Please refer to Figure 6 , in combination with the above embodiments, in some embodiments, the protruding portion 22 protrudes away from the accommodation cavity 11. The explosion-proof valve 20 includes a first transition portion 25. The first transition portion 25 is disposed between the protruding portion 22 and the recessed portion 23 and circumferentially connects to the recessed portion 23. The protruding portion 22 circumferentially connects to the first transition portion 25. The first transition portion 25 includes a first side surface 251. The first side surface 251 faces away from the accommodation cavity 11. The first side surface 251 is a plane and is perpendicular to the first direction X.

[0048] It can be understood that a first transition portion 25 can be connected between the protruding portion 22 and the recessed portion 23. The first transition portion 25 is a ring structure and can be arranged around the recessed portion 23. A first side surface 251 facing away from the accommodation cavity 11 can be provided on the first transition portion 25. The first side surface 251 can be a plane. When the first transition portion 25 is acted upon by an external object (the acting force is relatively uniform and perpendicular to the first side surface 251), the external object will first act on the first side surface 251 (the height of the first side surface 251 is greater than or equal to the height of the protruding portion 22 and also greater than or equal to the height of the recessed portion 23). Since the first side surface 251 is a plane, the planar first side surface 251 has a larger force-bearing area (the contact surface of the external object is also a plane), and can provide a larger planar area to disperse the local load. This structure can distribute the load more evenly to the entire explosion-proof valve 20 through the plane, avoiding the possible local stress concentration problem on the main body portion (the main body portion includes the protruding portion 22 and the recessed portion 23) of the explosion-proof valve 20.

[0049] Please refer to Figure 6 , in combination with the above embodiments, in some embodiments, the first transition portion 25 includes a second side surface 252. The second side surface 252 is arranged opposite to the first side surface 251, and the second side surface 252 is an arc surface.

[0050] It can be understood that the first transition portion 25 has two opposite surfaces in the first direction X. One is the first side surface 251 with a planar structure, and the first side surface 251 is arranged at the top of the first transition portion 25. The other is the second side surface 252 with an arc surface, and the second side surface 252 is arranged at the bottom of the first transition portion 25. The second side surface 252 faces the accommodation cavity 11 of the battery. When the battery undergoes thermal runaway, a large amount of gas will be generated inside the accommodation cavity 11. These gases will enter the through holes and squeeze the explosion-proof valve 20. Since the second side surface 252 on the explosion-proof valve 20 is an arc surface, it has a larger contact area with the gas generated inside the battery, making the extrusion force acting on the second side surface 252 by these gases per unit time greater. As a result, the main body portion of the explosion-proof valve 20 is timely torn at the position of the notch 24, and the explosion-proof valve 20 can open the valve in time to relieve pressure, ensuring the safety of the battery and avoiding the explosion of the battery caused by the explosion-proof valve 20 opening the valve too late.

[0051] Please refer to Figure 7 , in combination with the above embodiments, in some embodiments, the first transition portion 25 includes a third side surface 253. The third side surface 253 is arranged opposite to the first side surface 251, the third side surface 253 is a plane, and is perpendicular to the first direction X.

[0052] It can be understood that the first transition part 25 has two opposite faces in the first direction X. One is the first side face 251 set as a planar structure, and the first side face 251 is arranged at the top of the first transition part 25. The other is the third side face 253 set as a plane, and the third side face 253 is arranged at the bottom of the first transition part 25. The positions of the third side face 253 and the first side face 251 are correspondingly set, and their shapes and areas are basically the same. The purpose is to ensure that the thicknesses of the concave part 23, the convex part 22, and the first transition part 25 are basically the same, to avoid a smaller thickness at a certain part of the first transition part 25, resulting in a reduction in strength, causing the explosion-proof valve 20 to rupture before reaching the preset valve-opening pressure and preventing premature pressure relief; or to avoid a larger thickness at a certain part of the first transition part 25, which increases the processing cost and difficulty of the first transition part 25 (if the third side face 253 on the first transition part 25 is an arc face, the upward convex arc face will make the thickness of the first transition part 25 uneven, with some parts having a smaller thickness and lower strength, and being prone to rupture; if the arc face protrudes downward, it will also make the thickness of the first transition part 25 uneven, with some parts having a larger thickness, increasing the material consumption and cost, and also increasing the processing difficulty).

[0053] Please refer to Figure 8 , in combination with the above embodiments, in some embodiments, the explosion-proof valve 20 includes a second transition part 26. The second transition part 26 surrounds the convex part 22, and the convex part 22 is connected to the skirt part 21 through the second transition part 26. The notch 24 is arranged on the second transition part 26. The single cell satisfies: L1≥t1, and L1≥t2. Wherein, L1 is the thickness of the second transition part 26, t1 is the thickness of the convex part 22, and t2 is the thickness of the skirt part 21.

[0054] It can be understood that a second transition part 26 is arranged between the convex part 22 and the skirt part 21. The second transition part 26 surrounds the convex part 22, and the skirt part 21 surrounds the second transition part 26. Among them, the notch 24 is arranged on the second transition part 26. At the same time, the thickness L1 of the second transition part 26 is set to be larger, and it needs to be greater than or equal to the thickness t1 of the convex part 22 and the thickness t2 of the skirt part 21 (since the notch 24 is arranged on the second transition part 26, the thickness of the second transition part 26 can be set to be larger). When the notch 24 is arranged on the second transition part 26, the depth range of the notch 24 can be set to be larger, and then the value range of the valve-opening value of the explosion-proof valve 20 can be set to be wider, so that the explosion-proof valve 20 can be applied to batteries with different pressure relief requirements, improving the applicability of the explosion-proof valve 20.

[0055] Please refer to Figure 8 , in combination with the above embodiments, in some embodiments, the single cell satisfies: 0.15mm≤t1=t2≤0.2mm.

[0056] It can be understood that when the second transition portion 26 is disposed between the protruding portion 22 and the skirt portion 21, the thickness t1 of the protruding portion 22 and the thickness t2 of the skirt portion 21 are equal and within the range of 0.15 mm to 0.2 mm (including 0.15 mm and 0.2 mm). When the battery undergoes thermal runaway, the internal pressure will rise sharply, and the explosion-proof valve 20 needs to open at a specific pressure value to release gas (that is, to be torn at the position of the score 24 to release gas). The equal thickness of the protruding portion 22 and the skirt portion 21 helps to accurately set the opening pressure of the explosion-proof valve 20. When the pressure reaches the design value, the score 24 preferentially ruptures due to its relatively weak structure, enabling the gas to be released. If the thicknesses of the two are inconsistent, it may lead to a deviation in the opening pressure of the explosion-proof valve, and it cannot start pressure relief at the ideal pressure point. Either the pressure relief occurs prematurely, affecting the normal operation of the battery, or the pressure relief occurs too late, resulting in too high internal pressure of the battery and causing more serious problems. The equal thickness of the protruding portion 22 and the skirt portion 21 can also ensure that under the action of pressure, the rupture process at the score 24 is relatively stable and predictable, and there will be no abnormal rupture mode due to one part being too thick or too thin.

[0057] Please refer to Figure 8 , in combination with the above embodiments, in some embodiments, the explosion-proof valve 20 includes a connecting portion 27. The connecting portion 27 is disposed around the skirt portion 21, and the skirt portion 21 is connected to the inner wall of the through hole 12 through the connecting portion 27. The single battery satisfies: 0.4 mm ≤ D ≤ 0.6 mm; where D is the thickness of the connecting portion 27 in the first direction X.

[0058] It can be understood that the skirt portion 21 is connected to the inner wall of the through hole 12 through the connecting portion 27, and the thickness of the connecting portion 27 is within the range of 0.4 mm to 0.6 mm (including 0.4 mm and 0.6 mm). Within this range, the connecting portion 27 has a relatively large area for connection with the inner wall of the through hole 12, which can ensure the stability of the connection between the connecting portion 27 and the inner wall of the through hole 12. When the thickness of the connecting portion 27 is less than 0.4 mm, the connection area between the connecting portion 27 and the inner wall of the through hole 12 is small, the connection stability is low, and the connection difficulty increases, so it is not recommended to use. When the thickness of the connecting portion 27 is greater than 0.6 mm, the connecting portion 27 has a relatively large connection area with the inner wall of the through hole 12, but the volume of the connecting portion 27 is large, occupying more space, and the processing cost will also increase, so it is not recommended to use.

[0059] Please refer to Figure 4 , in combination with the above embodiments, in some embodiments, the thickness of the housing 10 is H, satisfying: 1 mm ≤ H ≤ 1.5 mm.

[0060] It can be understood that the thickness H of the housing 10 can be set between 1 mm and 1.5 mm (including 1 mm and 1.5 mm), such that the maximum dimensions of the connecting portion 27 and the protruding portion 22 in the first direction X are both smaller than the thickness H of the housing 10. Thus, the explosion-proof valve 20 can be installed in the through-hole 12, and there is no part of the explosion-proof valve 20 outside the through-hole 12. This setting method can provide a certain degree of protection for the explosion-proof valve 20 and reduce the probability of it being collided by external objects.

[0061] A battery pack includes the single battery as described above. The battery pack is used for storing and releasing electric energy, and includes a box body and a plurality of the single batteries as described above. The plurality of battery monomers are accommodated in the box body. Therefore, the battery pack has all the technical features and beneficial effects of the single battery as described above, and will not be elaborated herein too much.

[0062] An electrical device includes the single battery as described above, or includes the battery pack as described above.

[0063] 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.

[0064] The single battery, battery pack, and electrical device provided by the embodiments of the present application have been introduced in detail above, and specific examples have been used to elaborate the principle and implementation manner of the present application. The descriptions of the above embodiments are only used to help understand the technical solution and its core idea of the present application; those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A single cell battery, characterized in that: include: A shell having a receiving cavity and a through hole communicating with the receiving cavity; an explosion-proof valve connected to the housing and covering the through hole, the explosion-proof valve comprising a skirt portion, a protruding portion and a recessed portion, the protruding portion being arranged around the recessed portion and being connected to the recessed portion, the protruding portion being arranged to protrude along a first direction, the recessed direction of the recessed portion being opposite to the protruding direction of the protruding portion, the skirt portion being arranged around the protruding portion and being connected to the protruding portion, and a notch being arranged at the connection between the protruding portion and the skirt portion; The single cell battery satisfies: 0.43≤C / B≤0.78; The plane where the bottom of the skirt portion is located is the reference plane, B is the distance from the top of the protruding portion to the reference plane in the first direction, and C is the distance from the bottom of the recessed portion to the reference plane in the first direction.

2. The single cell according to claim 1, characterized in that: The protrusion is arranged to protrude away from the accommodating cavity, and the explosion-proof valve comprises: A first transition portion, wherein the first transition portion is disposed between the protruding portion and the recessed portion and surrounds the recessed portion, the protruding portion surrounds the first transition portion, the first transition portion includes a first side surface, the first side surface is disposed away from the accommodating cavity, the first side surface is a plane, and is perpendicular to the first direction.

3. The single cell according to claim 2, characterized in that: The first transition portion includes a second side surface, the second side surface is arranged opposite to the first side surface, and the second side surface is an arc-shaped surface.

4. The single cell according to claim 2, characterized in that: The first transition portion includes a third side surface, the third side surface is arranged opposite to the first side surface, and the third side surface is a plane and is perpendicular to the first direction.

5. The single cell according to claim 1, characterized in that: The explosion-proof valve comprises: a second transition portion, the second transition portion is arranged around the protruding portion, the protruding portion is connected to the skirt portion through the second transition portion, and the notch is arranged on the second transition portion; The single battery satisfies: L1≥t1, and L1≥t2; Wherein, L1 is the thickness of the second transition portion, t1 is the thickness of the protruding portion, and t2 is the thickness of the skirt portion.

6. The single cell according to claim 5, characterized in that: The single cell satisfies: 0.15 mm ≤ t1 = t2 ≤ 0.2 mm.

7. The single cell according to claim 1, characterized in that: The explosion-proof valve comprises a connecting portion, the connecting portion is arranged around the skirt portion, and the skirt portion is connected to the inner wall of the through hole through the connecting portion; The single cell meets the following requirements: 0.4 mm ≤ D ≤ 0.6 mm; Wherein, D is the thickness of the connecting portion in the first direction.

8. The single cell according to claim 1, characterized in that: The thickness of the shell is H, which satisfies: 1mm≤H≤1.5mm.

9. A battery pack, characterized in that: The invention comprises a single cell according to any one of claims 1 to 8.

10. An electrical device, characterized in that: The method comprises a single cell as claimed in any one of claims 1 to 8, or a battery pack as claimed in claim 9.

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