Single battery, battery pack and electric device

Abstract

The application discloses a single battery, a battery pack and an electric device, and belongs to the technical field of batteries.The single battery comprises a shell which has a containing cavity and a through hole in communication with the containing cavity. By arranging the convex part and the concave part which are both arc-shaped structures, external force can be effectively transmitted to the foundation or the supporting structure. Moreover, the convex part and the concave part can protect the explosion-proof valve. When the convex part is subjected to a relatively large force in the direction opposite to the protruding direction, the convex part can be deformed to a certain extent, so that the protruding part of the convex part is reduced and is changed into a concave part. When the concave part is subjected to a relatively large force in the direction opposite to the concave direction, the concave part can also be deformed to a certain extent, so that the concave part of the concave part is reduced, and the concave part is changed into a convex part. The change of the structure can also buffer the explosion-proof valve to a certain extent, avoid damage of the convex part caused by a relatively large force, and improve the safety.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of batteries, and particularly relates to a single battery, a battery pack and an electric device. BACKGROUND

[0002] The main function of the explosion-proof valve on the battery is pressure relief and exhaust. The explosion-proof valve is used for the directional release of high-temperature and high-pressure gas in the battery when the battery is in thermal runaway due to mechanical impact, internal abnormal interconnection short circuit and other reasons, so as to improve the safety performance of the battery pack. However, since the explosion-proof valve is in contact with the external environment, the structural strength is low, and the explosion-proof valve has a high risk of abnormal cracking and early valve opening under the action of external force. SUMMARY

[0003] The application aims to overcome the technical problem that the explosion-proof valve has a high risk of abnormal cracking and early valve opening under the action of external force. Another object of the application is to provide a battery pack. A third object of the application is to provide an electric device.

[0004] TECHNICAL SOLUTION The single battery provided by the application comprises:

[0005] A shell having a containing cavity and a through hole in communication with the containing cavity;

[0006] An explosion-proof valve connected with the shell 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 connected with the recessed portion, the protruding portion being arranged in a protruding manner along a first direction, the recessed portion being arranged in a recessed manner in a direction opposite to the protruding direction of the protruding portion, the skirt portion being arranged around the protruding portion and connected with the protruding portion, and an indentation being arranged at the connection between the protruding portion and the skirt portion;

[0007] The single battery satisfies 0.43<=C / B<=0.78.

[0008] The bottom of the skirt portion is located on 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.

[0009] In some embodiments, the protruding portion is arranged in a protruding manner away from the containing cavity, and the explosion-proof valve comprises:

[0010] A first transition portion arranged between the protruding portion and the recessed portion and connected with the recessed portion, the protruding portion being connected with the first transition portion, the first transition portion comprising a first side surface arranged away from the containing cavity, the first side surface being a plane and being perpendicular to the first direction.

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

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

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

[0014] a second transition portion, which is disposed around the protruding portion, and connects the protruding portion and the skirt portion through the second transition portion, and the score is disposed on the second transition portion;

[0015] The single battery 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 battery satisfies: 0.15mm≤t1=t2≤0.2mm.

[0018] In some embodiments, the explosion-proof valve comprises a connecting portion, which is disposed around the skirt portion, and connects the skirt portion and the inner wall of the through hole through the connecting portion.

[0019] The single battery 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 shell is H, which satisfies: 1mm≤H≤1.5mm.

[0022] A battery pack comprising the single battery of any one of the above.

[0023] A power utilization device comprising the single battery of any one of the above, or the battery pack of the above.

[0024] Beneficial effects: The single-cell battery of this application embodiment 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 sealing the through hole, the explosion-proof valve including a skirt, a protrusion and a recess, the protrusion surrounding the recess and connected to the recess, the protrusion protruding along a first direction, the recess direction of the recess being opposite to the protrusion direction of the protrusion, the skirt surrounding the protrusion and connected to the protrusion, and a groove being provided at the connection between the protrusion and the skirt; the single-cell battery satisfies: 0.43≤C / B≤0.78; wherein, the plane where the bottom of the skirt is located is a reference plane, B is the distance from the top of the protrusion in the first direction to the reference plane, and C is the distance from the bottom of the recess in the first direction to the reference plane. By incorporating protrusions and recesses with arc-shaped surfaces, external forces can be effectively transferred to the foundation or support structure, protecting the explosion-proof valve. Furthermore, when a protrusion is subjected to a large force in the opposite direction, it deforms, reducing its protrusion and transforming into a recess. Conversely, when a recess is subjected to a large force in the opposite direction, it deforms, reducing its concave portion and transforming into a protrusion. This structural change provides a buffer for the explosion-proof valve, preventing damage to the protrusions from excessive forces, improving its safety, and reducing the risk of abnormal cracking or premature valve opening. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 This is a perspective view of the housing according to an embodiment of this application;

[0027] Figure 2 This is a cross-sectional perspective view of the housing according to an embodiment of this application;

[0028] Figure 3 This is a front sectional view of the housing according to an embodiment of this application;

[0029] Figure 4 Examples of this application Figure 3 Enlarged view of area A in the middle;

[0030] Figure 5 This is a perspective view of the explosion-proof valve according to an embodiment of this application;

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

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

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

[0034] Reference numerals: 10-Housing shell; 11-Receiving cavity; 12-Through hole; 20-Explosion-proof valve; 21-Skirt; 22-Protrusion; 23-Recess; 24-Score; 25-First transition section; 251-First side; 252-Second side; 253-Third side; 26-Second transition section; 27-Connecting part; 30-Reference plane; X-First direction. Detailed Implementation

[0035] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0036] In the description of this application, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, features defined as "first" or "second" may explicitly or implicitly include one or more features. In the description of this application, "multiple" means two or more, and "at least one" can mean one, two, or more, unless otherwise explicitly specified.

[0037] The primary function of the explosion-proof valve on a battery is to release pressure and vent gas. It is used to release the high-temperature, high-pressure gas inside the battery in the event of thermal runaway due to mechanical impact, internal abnormal connections, or short circuits, thereby improving the safety performance of the battery pack. Currently, as individual battery cells are designed to be thinner, the size of the explosion-proof valve is also gradually decreasing. The key technical challenge is to rationally design the structure of the explosion-proof valve within limited length and width, ensuring that its opening value meets design requirements while improving its structural strength to reduce the risk of abnormal cracking and premature valve opening under external forces.

[0038] In view of the above, embodiments of this application provide a single-cell battery to overcome at least one of the above-mentioned technical problems.

[0039] Please see Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 and Figure 6 In this embodiment of the application, the single battery 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 protrusion 22 and a recessed portion 23. The protrusion 22 is arranged around the recessed portion 23 and is connected to the recessed portion 23. The protrusion 22 protrudes along a first direction X. The recessed direction of the recessed portion 23 is opposite to the protruding direction of the protrusion 22. The skirt portion 21 is arranged around the protrusion 22 and is connected to the protrusion 22. A groove 24 is provided at the connection between the protrusion 22 and the skirt portion 21.

[0041] Understandably, the explosion-proof valve 20 on a single battery cell is generally located on the battery cover. However, due to the increasingly thinner battery designs, the width of the cover connected to one side of the battery casing 10 is also decreasing. This limits the width of the explosion-proof valve 20, which was originally located on the cover. Consequently, the explosion-proof valve 20 cannot be properly positioned on the cover, potentially causing its opening value to fail to meet the battery design requirements. Therefore, in this application, the explosion-proof valve 20, originally located on the battery cover, is located on the battery casing 10 (e.g., ...). Figure 1 The width of the battery casing 10 is generally greater than or equal to the width of the cover plate (at least a portion of the cover plate needs to be embedded in the receiving cavity 11 of the casing 10, while reducing the space occupied by the cover plate, so the width of the cover plate is generally less than or equal to the width of the casing 10). Alternatively, the explosion-proof valve 20 can be located on other sides of the casing 10. Placing the explosion-proof valve 20 on the casing 10 provides more space for its installation, eliminating restrictions on its width and length, thus satisfying the structural dimensions of the explosion-proof valve 20 and ensuring its proper opening.

[0042] Meanwhile, when the explosion-proof valve 20 is arranged on the shell 10, and the opening valve value of the explosion-proof valve 20 meets the design requirements, the protruding portion 22 can be arranged on the explosion-proof valve 20, so that the protruding portion 22 is arranged in protrusion along the first direction X (along the first direction, the protruding portion 22 is arranged in protrusion from the skirt portion 21), so that the surface of the protruding portion 22 is at least partially arc-shaped, when an external force opposite to the protruding direction of the protruding portion 22 acts on the protruding portion 22, the force acting on the protruding portion 22 is effectively transmitted to the foundation or support structure through the protruding portion 22, that is, to the skirt portion 21, and the skirt portion 21 is connected with the shell 10, so that part of the force is transmitted to the shell 10. Moreover, when the protruding portion 22 is subjected to a larger force opposite to the protruding direction thereof, the protruding portion 22 can be deformed to a certain extent, so that the protruding part of the protruding portion 22 is reduced and is changed into a recessed part (the protruding part of the protruding portion 22 can be partially changed into a recessed part, or can be completely changed into a recessed part), and the change in structure can play a certain buffering role for the explosion-proof valve 20, avoid damage of the protruding portion 22 due to a larger force, and improve the safety thereof. The recessed portion 23 is also arranged on the explosion-proof valve 20, the protruding portion 22 surrounds the recessed portion 23, the surface of the recessed portion 23 is at least partially arc-shaped, and the recessed direction of the recessed portion 23 is opposite to the protruding direction of the protruding portion 22. When an external force opposite to the recessed direction of the recessed portion 23 acts on the recessed portion 23, the force acting on the recessed portion 23 is effectively transmitted to the foundation or support structure through the recessed portion 23, that is, to the protruding portion 22, and the protruding portion 22 is connected with the shell 10 through the skirt portion 21, so that part of the force is transmitted to the shell 10. Moreover, when the recessed portion 23 is subjected to a larger force opposite to the recessed direction thereof, the recessed portion 23 can also be deformed to a certain extent, so that the recessed part of the recessed portion 23 is reduced, so that the recessed part is changed into a protruding part (the recessed part of the recessed portion 23 can be partially changed into a protruding part, or can be completely changed into a protruding part), and the change in structure can also play a certain buffering role for the explosion-proof valve 20, avoid damage of the recessed portion 23 due to a larger force, and improve the safety thereof.

[0043] The single battery satisfies: 0.43≤C / B≤0.78; wherein the plane where the bottom of the skirt portion 21 is located is the reference surface 30, B is the distance from the top of the protruding portion 22 to the reference surface 30 in the first direction X, and C is the distance from the bottom of the recessed portion 23 to the reference surface 30 in the first direction X. It can be understood that the ratio of the distance from the bottom of the recessed portion 23 to the reference surface 30 in the first direction X to the distance from the top of the protruding portion 22 to the reference surface 30 in the first direction X is within the range of 0.43 to 0.78 (for example, 0.43≤C / B≤0.78). 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 a range value between any two values. When in the range, the pressure resistance of the convex portion 22 and the concave portion 23 can be effectively improved, and the structural strength of the convex portion 22 and the concave portion 23 can be ensured to a certain extent (the convex portion 22 and the concave portion 23 constitute the main part of the explosion-proof valve 20, improving the structural strength of the convex portion 22 and the concave portion 23 can improve the structural strength of the explosion-proof valve 20), so as to avoid the convex portion 22 and the concave portion 23 from being easily damaged or prematurely opened when extruded by external force. The values of C and B can be measured by a caliper or a three-dimensional scanner. It should be noted that when testing the explosion-proof valve 20 in the embodiment of the present application, multiple groups of batteries with the explosion-proof valve 20 installed are tested (the ratio of C to B on each group of explosion-proof valve 20 is different), and the explosion-proof valve 20 can be subjected to an action force of 0.4 Mpa along the first direction X, and whether the convex portion 22 and the concave portion 23 are broken is observed. The test results of the examples and the comparative examples are as follows:

[0044]

[0045]

[0046] As can be seen from the above table, when a certain force is applied to the protrusion 22 and the recess 23 along the first direction X, in the case where the value of C / B is in the range of 0.43 to 0.78 (including 0.43 and 0.78), the protrusion 22 and the recess 23 do not have the phenomenon of cracking, which indicates that the protrusion 22 and the recess 23 in this case have good compression resistance, and the risk of abnormal cracking and early opening of the explosion-proof valve 20 can be reduced. When the value of C / B is less than 0.43, at least one of the protrusion 22 and the recess 23 cracks, which may be due to the fact that the recess 23 has a large recess degree (that is, the value of C is small), so that the curvature of the arch-shaped structure formed by the recess 23 is too large (the curvature refers to the degree of bending of a geometric body), and the stability of the arch-shaped structure is reduced, and the compression resistance is reduced, so that the arch-shaped structure may crack under the action of force. Or it may be due to the fact that the protrusion 22 has a large protrusion degree (that is, the value of D is large), so that the curvature of the arch-shaped structure formed by the protrusion 22 is too large, which reduces the stability of the arch-shaped structure and reduces the compression resistance, so that the arch-shaped structure may crack under the action of force. When the value of C / B is greater than 0.78, at least one of the protrusion 22 and the recess 23 cracks, which may be due to the fact that the recess 23 has a small recess degree (that is, the value of C is large), so that the curvature of the arch-shaped structure formed by the recess 23 is too small, and the small curvature reduces the support effect of the structure and reduces the compression resistance, so that the arch-shaped structure may crack under the action of force. Or it may be due to the fact that the protrusion 22 has a small protrusion degree (that is, the value of D is small), so that the curvature of the arch-shaped structure formed by the protrusion 22 is too small, which reduces the support effect of the protrusion 22 and reduces the compression resistance, so that the arch-shaped structure may crack under the action of force.

[0047] Please refer to Figure 6 , in combination with the above embodiments, in some embodiments, the protrusion 22 is arranged to protrude away from the accommodation cavity 11, the explosion-proof valve 20 comprises a first transition portion 25, the first transition portion 25 is arranged between the protrusion 22 and the recess 23 and surrounds the recess 23, the protrusion 22 surrounds the first transition portion 25, and the first transition portion 25 comprises a first side surface 251, the first side surface 251 is arranged away from the accommodation cavity 11, and the first side surface 251 is a plane and is perpendicular to the first direction X.

[0048] It can be understood that the first transition portion 25 can be connected between the convex portion 22 and the concave portion 23, the first transition portion 25 has a ring structure and can be arranged around the concave portion 23. The first transition portion 25 can be provided with a first side surface 251 away from the accommodating cavity 11, and the first side surface 251 can be a plane. When the first transition portion 25 is subjected to an external force (the force is relatively uniform and perpendicular to the first side surface 251), the external force 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 convex portion 22, and also greater than or equal to the height of the concave portion 23). Since the first side surface 251 is a plane, the plane structure of the first side surface 251 has a larger stress area (the contact surface of the external object is also a plane), which can provide a larger plane area to disperse the local load. This structure can more evenly distribute the load to the entire explosion-proof valve 20 through the plane, avoiding the local stress concentration problem that may occur on the main body portion (including the convex portion 22 and the concave 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 arranged as a plane structure, and the first side surface 251 is arranged at the top of the first transition portion 25, and the other is the second side surface 252 arranged as 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 is arranged towards the accommodating cavity 11 of the battery. When the battery is in thermal runaway, a large amount of gas will be generated inside the accommodating cavity 11, which will enter the through hole and press the explosion-proof valve 20. Since the second side surface 252 of the explosion-proof valve 20 is an arc surface, it has a larger contact area with the gas generated inside the battery, so that the extrusion force of the gas on the second side surface 252 per unit time is larger, thereby tearing the main body portion of the explosion-proof valve 20 at the position of the notch 24 in time. The explosion-proof valve 20 can open and vent in time, ensuring the safety of the battery and avoiding the explosion of the battery caused by the explosion-proof valve 20 opening 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, and the third side surface 253 is a plane and perpendicular to the first direction X.

[0052] It can be understood that the first transition portion 25 has two faces arranged opposite to each other in the first direction X, one is a first side face 251 arranged as a flat structure, the first side face 251 is arranged at the top of the first transition portion 25, and the other is a third side face 253 arranged as a flat structure, the third side face 253 is arranged at the bottom of the first transition portion 25. The third side face 253 and the first side face 251 are arranged in a corresponding position, and the shapes and areas of the two are basically the same, the purpose is to ensure that the thicknesses of the recess portion 23, the protruding portion 22 and the first transition portion 25 are basically the same, avoid that the thickness of a certain part of the first transition portion 25 is smaller, the strength is reduced, the explosion-proof valve 20 is broken before reaching the preset opening valve pressure, and the early pressure relief is prevented; or the thickness of a certain part of the first transition portion 25 can be avoided to be larger, so that the processing cost and the processing difficulty of the first transition portion 25 are increased (if the third side face 253 of the first transition portion 25 is an arc face, the arc face protrudes upward, which will make the thickness of the first transition portion 25 uneven, some parts have smaller thickness and lower strength, and are easy to break; if the arc face protrudes downward, it will also make the thickness of the first transition portion 25 uneven, some parts have larger thickness, which will increase the material and cost, and also increase the processing difficulty).

[0053] Please refer to Figure 8 , in combination with the above embodiments, in some embodiments, the explosion-proof valve 20 comprises a second transition portion 26. The second transition portion 26 is arranged around the protruding portion 22, the protruding portion 22 is connected with the skirt portion 21 through the second transition portion 26, and the score 24 is arranged on the second transition portion 26. The single battery satisfies: L1≥t1, and L1≥t2. Wherein, L1 is the thickness of the second transition portion 26, t1 is the thickness of the protruding portion 22, and t2 is the thickness of the skirt portion 21.

[0054] It can be understood that the second transition portion 26 is arranged between the protruding portion 22 and the skirt portion 21, the second transition portion 26 is arranged around the protruding portion 22, the skirt portion 21 is arranged around the second transition portion 26, and the score 24 is arranged on the second transition portion 26. At the same time, the thickness L1 of the second transition portion 26 is set to be larger, which needs to be greater than or equal to the thickness t1 of the protruding portion 22 and the thickness t2 of the skirt portion 21 (since the score 24 is arranged on the second transition portion 26, the thickness of the second transition portion 26 can be set to be larger). When the score 24 is arranged on the second transition portion 26, the depth range of the score 24 can be set to be larger, and then the value range of the opening valve 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, and the applicability of the explosion-proof valve 20 is improved.

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

[0056] It can be understood that, when the second transition portion 26 is arranged 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 in the range of 0.15 mm to 0.2 mm (including 0.15 mm and 0.2 mm). When the battery is in thermal runaway, the internal pressure will rise sharply, and the explosion-proof valve 20 needs to be opened at a certain pressure value to release the gas (that is, torn at the position of the notch 24 to release the 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 designed value, the notch 24 is preferentially broken due to the relatively weak structure, so that the gas can be released. If the thicknesses are inconsistent, the explosion-proof valve opening pressure may deviate, and the pressure relief may not be started at the ideal pressure point, which may affect the normal operation of the battery, or the pressure relief may be too late, which may cause the battery internal pressure to be too high and cause more serious problems. The equal thickness of the protruding portion 22 and the skirt portion 21 can also ensure that the breaking process at the notch 24 is relatively stable and predictable under the action of pressure, and abnormal breaking patterns will not occur due to the thickness 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 comprises a connecting portion 27, the connecting portion 27 is arranged 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; wherein 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 in the range of 0.4 mm to 0.6 mm (including 0.4 mm and 0.6 mm). When the thickness of the connecting portion 27 is in this range, the connecting portion 27 has a larger area to connect 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 connecting area between the connecting portion 27 and the inner wall of the through hole 12 is small, the stability of the connection is low, and the difficulty of the connection is increased, which is not recommended. When the thickness of the connecting portion 27 is greater than 0.6 mm, the connecting portion 27 has a larger connecting area with the inner wall of the through hole 12, but the volume of the connecting portion 27 is larger, the space occupied is more, and the processing cost is also increased, which is not recommended.

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

[0060] It can be understood that the thickness H of the shell 10 can be set between 1mm to 1.5mm (including 1mm and 1.5mm), so that the maximum dimension of the connecting portion 27 and the protruding portion 22 in the first direction X is less than the thickness H of the shell 10, so that the explosion-proof valve 20 can be installed in the through hole 12, and the explosion-proof valve 20 has no part outside the through hole 12, which can protect the explosion-proof valve 20 to a certain extent and reduce the probability of being collided by external objects.

[0061] A battery pack comprising the monomer battery described above. The battery pack is used for storing and releasing electric energy, comprising a box body and a plurality of monomer batteries described above, and the plurality of battery monomers are accommodated in the box body, so that the battery pack has all the technical features and beneficial effects of the monomer battery described above, which will not be described in detail here.

[0062] A use electric device comprising the monomer battery described above, or comprising the battery pack described above.

[0063] In the above embodiments, the description of each embodiment has its own focus, and the parts not described in detail in a certain embodiment can be referred to the related description of other embodiments.

[0064] The monomer battery, the battery pack and the use electric device provided by the embodiments of the present application are described in detail above, and the principles and implementation manners of the present application are described by applying specific examples. The above description of the embodiments is only used to help understand the technical solutions of the present application and its core idea; those skilled in the art should understand that the technical solutions recorded in the above embodiments can still be modified, or some technical features can be replaced by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A single cell, characterized by, The single battery comprises: a housing having a receiving cavity and a through hole in communication with the receiving cavity; an explosion-proof valve connected with the housing and covering the through hole, the explosion-proof valve comprising a skirt portion, a convex portion and a concave portion, the convex portion and the concave portion are both in an arched structure, the convex portion is arranged around the concave portion and connected with the concave portion, the convex portion is arranged in a convex manner in a first direction, the concave direction of the concave portion is opposite to the convex direction of the convex portion, the skirt portion is arranged around the convex portion and connected with the convex portion, a notch is arranged at the connection between the convex portion and the skirt portion, the notch is torn at the opening pressure of the explosion-proof valve to release gas; the single battery satisfies 0.43≤C / B≤0.78; wherein, a plane where the bottom of the skirt portion is located is a reference plane, B is the distance from the top of the convex portion to the reference plane in the first direction, and C is the distance from the bottom of the concave portion to the reference plane in the first direction; the convex portion is arranged in a convex manner away from the receiving cavity, and the explosion-proof valve comprises: a first transition portion arranged between the convex portion and the concave portion and connected around the concave portion, the convex portion is connected around the first transition portion, the first transition portion comprises a first side surface arranged away from the receiving cavity, the first side surface is a plane and perpendicular to the first direction.

2. The cell according to claim 1, wherein the first transition portion comprises a second side surface arranged opposite to the first side surface, the second side surface is an arc surface.

3. The cell according to claim 1, wherein the first transition portion comprises a third side surface arranged opposite to the first side surface, the third side surface is a plane and perpendicular to the first direction.

4. The cell according to claim 1, wherein the explosion-proof valve comprises: a second transition portion arranged around the convex portion, the convex portion is connected with 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 convex portion, and t2 is the thickness of the skirt portion.

5. The cell according to claim 4, wherein the single battery satisfies 0.15mm≤t1=t2≤0.2mm.

6. The cell according to claim 1, wherein the explosion-proof valve comprises a connecting portion arranged around the skirt portion, and the skirt portion is connected with the inner wall of the through hole through the connecting portion; the single battery satisfies 0.4mm≤D≤0.6mm; wherein, D is the thickness of the connecting portion in the first direction.

7. The cell according to claim 1, wherein the thickness of the housing is H, and satisfies 1mm≤H≤1.5mm.

8. A battery pack, characterized by, The battery pack comprises the single battery according to any one of claims 1 to 7.

9. An electric device, characterized by The battery pack comprises the single battery according to any one of claims 1 to 7 or the battery pack according to claim 8.

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