A single cell and a battery pack

Abstract

The application provides a single battery and a battery pack, and belongs to the technical field of batteries. The single battery comprises a shell, a top cover, an explosion-proof valve and an electrode assembly; the shell has a bottom wall; the top cover is connected with one end of the shell along a first direction and is arranged opposite to the bottom wall along the first direction; the explosion-proof valve is arranged on the bottom wall; the electrode assembly is arranged in the shell; the explosion-proof valve comprises an explosion-proof valve body and a mounting portion, the mounting portion is connected around the explosion-proof valve body, and the mounting portion is connected with the bottom wall; the explosion-proof valve body has a center portion and a protruding portion, the protruding portion is connected around the center portion, one side of the protruding portion, which is away from the center portion, is connected with the mounting portion, the center portion is recessed towards one side close to the electrode assembly along the first direction, and the protruding portion is protruded towards one side away from the electrode assembly. The single battery provided by the application recesses the center portion of the explosion-proof valve body towards one side close to the electrode assembly to form a buffer space, so that the impact from the outside can form a buffering effect, and the stability and strength of the explosion-proof valve are ensured.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to a single cell battery and a battery pack. Background Technology

[0002] During operation, new energy vehicles often encounter impacts from stones or other obstacles kicked up from the road, which can damage the battery pack. Although the battery pack is designed to avoid these impacts, the cells are still at risk of being damaged by stress. This is especially true for cells with inverted explosion-proof valves, where the structurally weak valves are directly exposed to the impact, making them more susceptible to damage and potentially leading to safety accidents. Utility Model Content

[0003] In view of this, the purpose of this application is to overcome the shortcomings of the prior art and provide a single cell battery and a battery pack.

[0004] This application provides the following technical solution: a single-cell battery, having a first orientation, comprising: The shell has a bottom wall; The top cover is connected to one end of the housing along the first direction and is disposed opposite to the bottom wall along the first direction; An explosion-proof valve is installed on the bottom wall; Electrode assemblies are disposed within the housing; The explosion-proof valve includes an explosion-proof valve body and a mounting part, the mounting part being connected to the explosion-proof valve body around it and connected to the bottom wall; The explosion-proof valve body has a central portion and a protruding portion. The protruding portion is connected around the central portion. The side of the protruding portion away from the central portion is connected to the mounting portion. The central portion is recessed towards the electrode assembly along the first direction, and the protruding portion protrudes towards the side away from the electrode assembly.

[0005] In some embodiments, the single cell further includes a connecting portion, the mounting portion is connected to the protrusion via the connecting portion, the connecting portion surrounds the protrusion, and the connecting portion has a weak portion on the side opposite to the electrode assembly.

[0006] In some embodiments, the weak portion is located at the edge of the connecting portion, the weak portion having a first end and a second end, the first end and the second end being located on one side of the edge of the connecting portion, and a gap being between the first end and the second end.

[0007] In some embodiments, the single cell has a second direction perpendicular to the first direction, and the bottom wall has a third end and a fourth end disposed opposite to each other along the second direction; The explosion-proof valve is located near the third end or the fourth end; or, the bottom wall is provided with two explosion-proof valves, one of which is located near the third end and the other is located near the fourth end.

[0008] In some embodiments, the single cell has a third direction that is perpendicular to both the first direction and the second direction; The explosion-proof valve has a fifth end and a sixth end arranged opposite to each other along the second direction, and the difference between the distances of the fifth end and the sixth end to one side of the bottom wall along the third direction is greater than zero.

[0009] In some embodiments, the explosion-proof valve has a plurality of spaced grooves on the side facing the electrode assembly; At least a portion of the groove is provided at the center of the central portion, and / or at least a portion of the groove is provided at the protrusion of the edge portion, and / or at least a portion of the groove is provided at the connecting portion.

[0010] In some embodiments, the bottom wall is provided with a plurality of explosion-proof valves, which are arranged at intervals along the second direction.

[0011] In some embodiments, the central portion is provided with a plurality of spaced first protrusions on the side facing the electrode assembly, and the cross-sectional area of ​​the first protrusions gradually increases along the first direction from the end closer to the electrode assembly to the end farther away from the electrode assembly. And / or the connecting portion is provided with a plurality of spaced second protrusions on the side facing the electrode assembly, the cross-sectional area of ​​the second protrusions gradually increasing along the first direction from the end closer to the electrode assembly to the end farther away from the electrode assembly.

[0012] In some embodiments, the single battery cell further includes a base plate disposed between the electrode assembly and the bottom wall. The base plate has a first clearance groove on the side facing the explosion-proof valve body, and the middle part of the central portion protrudes from the side facing the base plate and is received in the first clearance groove.

[0013] In some embodiments, the explosion-proof valve is provided with lugs on two opposite sides along the third direction, and the edge of the lug facing the electrode assembly is provided with a recess, which is recessed towards the side closer to the electrode assembly along the first direction.

[0014] Secondly, this application provides a battery pack including the aforementioned single battery cell.

[0015] The embodiments of this application have the following advantages: by recessing the center of the explosion-proof valve body towards the electrode assembly along the first direction and forming a clearance buffer space, the explosion-proof valve can provide clearance and buffer when impacted by an object outside the housing, thereby reducing the deformation of the explosion-proof valve when impacted, thus providing a buffering effect against external impacts, and ensuring the stability and strength of the explosion-proof valve.

[0016] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This paper shows a schematic diagram of the structure of a first embodiment of a single-cell battery provided by some embodiments of this application; Figure 2 This paper shows a schematic diagram of the structure of a single-cell battery according to some embodiments of the present application from another perspective. Figure 3 It shows Figure 2 Sectional view of section AA; Figure 4 It shows Figure 3 Enlarged view of section B; Figure 5 This illustration shows a schematic diagram of a first embodiment of an explosion-proof valve in a single-cell battery, provided by some embodiments of this application. Figure 6 This invention provides a schematic diagram of the structure of a first embodiment of an explosion-proof valve in a single-cell battery, according to some embodiments of this application, from another perspective. Figure 7 It shows Figure 6 Sectional view of the middle BB section; Figure 8 This invention provides a schematic diagram of the structure of a second embodiment of an explosion-proof valve in a single-cell battery, according to some embodiments of this application. Figure 9 This invention provides a schematic diagram of the structure of a bottom support plate in a single-cell battery according to some embodiments of the present application. Figure 10This illustration shows a schematic diagram of the structure of a first embodiment of a protective sheet in a single-cell battery according to some embodiments of this application; Figure 11 This invention provides a schematic diagram of the structure of a second embodiment of a protective sheet in a single-cell battery, according to some embodiments of this application. Figure 12 This illustration shows a schematic diagram of a third embodiment of an explosion-proof valve in a single-cell battery, provided by some embodiments of this application. Figure 13 This invention provides a schematic diagram of the structure of a fourth embodiment of an explosion-proof valve in a single-cell battery, according to some embodiments of this application. Figure 14 This invention provides a schematic diagram of the structure of a second embodiment of a single-cell battery according to some embodiments of the present application. Figure 15 This invention provides a schematic diagram of the structure of a third embodiment of a single-cell battery according to some embodiments of the present application. Figure 16 The diagram shows a structural schematic from one perspective of a fourth embodiment of a single-cell battery provided by some embodiments of this application.

[0019] Explanation of key component symbols: 100-Housing; 110-Bottom wall; 111-Third end; 112-Fourth end; 200-Explosion-proof valve; 210-Explosion-proof valve body; 211-Center; 212-Protrusion; 220-Mounting part; 221-Connecting part; 222-Weak part; 2221-First end; 2222-Second end; 230-Groove; 240-First protrusion; 250-Second protrusion; 260-Ear; 261-Recess; 270-Fifth end; 280-Sixth end; 300-Electrode assembly; 400-Bottom support plate; 410-First clearance groove; 500-Protective plate; 510-Vent hole; 600-Top cover.

[0020] Z - First direction; X - Second direction; Y - Third direction. Detailed Implementation

[0021] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0022] It should be noted that when an element is said to be "fixed" to another element, it can be directly on the other element or there may be an intervening element. When an element is said to be "connected" to another element, it can be directly connected to the other element or there may be an intervening element. Conversely, when an element is said to be "directly" on another element, there is no intervening element. The terms "vertical," "horizontal," "left," "right," and similar expressions used in this document are for illustrative purposes only.

[0023] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0024] Furthermore, 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. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0025] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the template description is for the purpose of describing particular embodiments only and is not intended to be limiting of this application. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0026] like Figures 1 to 5 As shown, some embodiments of this application provide a single-cell battery having a first direction Z. The single-cell battery includes a housing 100, a top cover 600, an explosion-proof valve 200, and an electrode assembly 300.

[0027] The housing 100 has a bottom wall 110, which is located on one side of the housing 100 along the first direction Z.

[0028] The top cover 600 is connected to one end of the housing 100 along the first direction Z, and the top cover 600 and the bottom wall 110 are disposed opposite each other along the first direction Z, so as to seal the housing 100 by means of the top cover 600, thereby forming a sealed receiving cavity inside the housing 100.

[0029] An explosion-proof valve 200 is disposed on the bottom wall 110. The explosion-proof valve 200 can be disposed at any position on the bottom wall 110. In addition, the tilt angle of the explosion-proof valve 200 on the bottom wall 110 can be specifically set according to the actual situation, so as to control the pressure inside the housing 100 through the explosion-proof valve 200. When the pressure inside the single cell is too high, the explosion-proof valve 200 will open under the action of pressure, thereby releasing the high-pressure gas generated inside the single cell to the external environment, thereby reducing the pressure inside the single cell and effectively preventing the risk of single cell explosion.

[0030] The electrode assembly 300 is disposed within the housing 100 to provide protection and limit the electrode assembly 300 through the housing 100 and the top cover 600, so as to ensure the stability of the electrode assembly 300 within the housing 100.

[0031] In this embodiment, the explosion-proof valve 200 includes an explosion-proof valve body 210 and a mounting portion 220. The mounting portion 220 is connected to the edge of the explosion-proof valve body 210 and is integrally formed with the explosion-proof valve body 210. The mounting portion 220 is connected to the bottom wall 110, thereby connecting the explosion-proof valve body 210 to the bottom wall 110 through the mounting portion 220. It is understood that by providing the mounting portion 220 on the edge of the explosion-proof valve body 210 to indirectly connect the explosion-proof valve body 210 to the bottom wall 110, deformation of the explosion-proof valve body 210 during connection with the bottom wall 110 is avoided, thus ensuring the stability of the explosion-proof valve body 210.

[0032] The explosion-proof valve body 210 has a central portion 211 and a protrusion 212. The protrusion 212 is connected to the central portion 211 around it, i.e., the protrusion 212 is located on the edge of the central portion 211. The side of the protrusion 212 away from the central portion 211 is connected to the mounting portion 220. The central portion 211 is recessed along the first direction Z towards the electrode assembly 300, and the protrusion 212 protrudes towards the side away from the electrode assembly 300, forming a wave-shaped structure on the side of the explosion-proof valve body 210 facing the electrode assembly 300. The side of the explosion-proof valve body 210 facing away from the electrode assembly 300 forms a wave-shaped structure so that when the explosion-proof valve body 210 is subjected to concentrated stress from external impact (such as ball impact) on the side facing away from the electrode assembly 300, the protrusion 212 can prolong the impact time and effectively disperse the impact force to the entire surface of the explosion-proof valve body 210. This prevents a single point or local area of ​​the explosion-proof valve body 210 from bearing all the impact force and forms a buffer against external impacts, so as to prevent the explosion-proof valve 200 from being damaged under external impacts and thus causing safety accidents. This significantly improves the impact resistance and structural reliability of the battery cell explosion-proof valve 200.

[0033] like Figures 5 to 8 As shown, in some embodiments of this application, the single battery cell further includes a connecting portion 221. The mounting portion 220 is connected to the protrusion 212 through the connecting portion 221. That is, the connecting portion 221 is disposed between the mounting portion 220 and the protrusion 212, and the connecting portion 221 surrounds the protrusion 212. The connecting portion 221 has a weak portion 222 on the side away from the electrode assembly 300. It can be understood that the thickness of the weak portion 222 along the first direction Z is less than the thickness of other areas on the connecting portion 221 along the first direction Z, so that when the internal pressure of the battery exceeds a predetermined pressure, the weak portion 222 is burst, thereby allowing the gas inside the casing 100 to be discharged from the weak portion 222 to release the pressure inside the casing 100.

[0034] In this embodiment, the connecting part 221, the mounting part 220 and the protrusion 212 are integrally connected to ensure the strength and stability of the explosion-proof valve 200.

[0035] like Figure 5 , Figure 6 and Figure 8 As shown, in some embodiments of this application, the weak portion 222 is located at the edge of the connecting portion 221. The weak portion 222 has a first end 2221 and a second end 2222. The first end 2221 and the second end 2222 are respectively located on one side of the edge of the connecting portion 221, and there is a gap between the first end 2221 and the second end 2222. That is, the thickness of the area corresponding to the first end 2221 and the second end 2222 in the first direction Z is the same as the thickness of the area of ​​the connecting portion 221 other than the weak portion 222 in the first direction Z. This is to prevent the weak portion 222 from bursting when the pressure inside the housing 100 is greater than a predetermined pressure, causing the explosion-proof valve body 210 to fall off the mounting portion 220, thereby ensuring the stability of the connection between the explosion-proof valve body 210 and the mounting portion 220.

[0036] In this embodiment, the weak part 222 is a groove 230, that is, the groove 230 is recessed along the first direction Z towards the side close to the electrode assembly 300.

[0037] like Figure 14 As shown, in some embodiments of this application, the single cell has a second direction X perpendicular to the first direction Z, the bottom wall 110 has a third end 111 and a fourth end 112 disposed opposite to each other along the second direction X, and the explosion-proof valve 200 is close to the third end 111 or the fourth end 112.

[0038] In some embodiments, the bottom wall 110 is provided with two explosion-proof valves 200, one of which is close to the third end 111 and the other is close to the fourth end 112. It should be noted that by biasing the explosion-proof valves 200 away from the high-stress central area of ​​the electrode assembly 300 along the first direction Z toward the bottom wall 110, the probability of the explosion-proof valves 200 being mistakenly opened due to mechanical impact in non-thermal runaway scenarios can be effectively reduced. Furthermore, by setting a certain tilt angle for the explosion-proof valves 200, the gas outflow direction can be changed, mitigating the impact of gas on the explosion-proof valves 200.

[0039] like Figures 5 to 7 As shown, in some embodiments of this application, the single cell has a third direction Y that is mutually perpendicular to both the first direction Z and the second direction X.

[0040] The explosion-proof valve 200 has a fifth end 270 and a sixth end 280 arranged opposite to each other along the second direction X. The difference between the distances of the fifth end 270 and the sixth end 280 to one side of the bottom wall 110 along the third direction Y is greater than zero, thereby offsetting the explosion-proof valve 200 on the bottom wall 110. By controlling the inclination of the explosion-proof valve 200 with respect to the second direction X, the direction of gas outflow inside the housing 100 can be effectively changed, thereby reducing the impact of gas on the explosion-proof valve 200.

[0041] It is understandable that by biasing the explosion-proof valve 200 on the bottom wall 110 and moving the explosion-proof valve 200 away from the electrode assembly 300 toward the high-stress area in the center of the bottom wall 110, the probability of accidental opening due to mechanical impact in non-thermal runaway scenarios can be reduced.

[0042] like Figure 13 As shown, in some embodiments of this application, the explosion-proof valve 200 has a plurality of spaced grooves 230 on the side facing the electrode assembly 300. The number of grooves 230 can be specifically set according to the actual situation.

[0043] In some embodiments, at least a portion of the grooves 230 are disposed on the center portion 211, and a plurality of grooves 230 are arranged at equal intervals on the center portion 211; in some embodiments, at least a portion of the grooves 230 are disposed on the edge portion protrusion 212, and a plurality of grooves 230 are arranged at equal intervals on the protrusion 212; in some embodiments, at least a portion of the grooves 230 are disposed on the connecting portion 221, and a plurality of grooves 230 are arranged at equal intervals on the connecting portion 221.

[0044] It should be noted that when the gas inside the housing 100 impacts the side of the explosion-proof valve 200 facing the electrode assembly 300, the gas forms a vortex in the groove 230. The gas in the vortex converts the kinetic energy (energy) of the airflow into heat energy through internal fluid friction. Furthermore, the vortex in the groove 230 is relatively stable and forms a nearly stationary or slowly moving air layer above the groove 230, thereby achieving a buffering effect.

[0045] like Figure 15 and Figure 16 As shown in some embodiments of this application, the bottom wall 110 is provided with a plurality of explosion-proof valves 200, which are arranged at intervals along the second direction X. The number of explosion-proof valves 200 can be any number of two or more values. Furthermore, the angle between the extension direction of the explosion-proof valve 200 and the second direction X can be specifically set according to actual conditions. By setting multiple explosion-proof valves 200, the pressure relief area is increased, the pressure relief capacity is enhanced, and the pressure relief delay is reduced, thereby establishing multiple redundant pressure relief paths to cope with complex and extreme thermal runaway scenarios and improve the reliability of pressure relief.

[0046] like Figure 12 As shown, in some embodiments of this application, the central portion 211 has a plurality of spaced-apart first protrusions 240 on the side facing the electrode assembly 300. The cross-sectional area of ​​the first protrusions 240 gradually increases along the first direction Z from the end closer to the electrode assembly 300 to the end farther away from the electrode assembly 300. It is understood that the first protrusions 240 can be any of a conical protrusion, a hemispherical protrusion, or a polygonal pyramidal protrusion, and can be specifically set according to the actual situation.

[0047] In some embodiments, a plurality of first protrusions 240 are arranged at equal intervals. The arrangement of the first protrusions 240 is such that when the first protrusion 240 is impacted by external gas, the end of the first protrusion 240 facing the electrode assembly 300 along the first direction Z can cut the gas and generate turbulence, thereby dispersing the impact force on the center part 211, so as to ensure the stability of the gas pressure on each part of the explosion-proof valve body 210.

[0048] In some embodiments, the connecting portion 221 has a plurality of spaced second protrusions 250 on the side facing the electrode assembly 300, and the cross-sectional area of ​​the second protrusions 250 gradually increases along the first direction Z from the end closer to the electrode assembly 300 to the end farther away from the electrode assembly 300. It is understood that the second protrusions 250 can be any of the following: a conical protrusion, a hemispherical protrusion, or a polygonal pyramidal protrusion, and can be specifically set according to the actual situation.

[0049] It should be noted that multiple second protrusions 250 are arranged at equal intervals. The arrangement of the second protrusions 250 allows them to cut the gas at the end of the second protrusion 250 facing the electrode assembly 300 along the first direction Z when impacted by external gas, generating turbulence and dispersing the impact force on the central part 211. This ensures the stability of the gas pressure on each part of the explosion-proof valve body 210, enabling the explosion-proof valve 200 to explode precisely in a directional manner, thus ensuring the reliability, safety, and controllability of the explosion-proof valve 200.

[0050] like Figure 3 , Figure 4 , Figure 7 and Figure 9 As shown in some embodiments of this application, the single battery cell further includes a base plate 400, which is disposed between the electrode assembly 300 and the bottom wall 110. The base plate 400 has a first clearance groove 410 on the side facing the explosion-proof valve body 210. The middle part of the central portion 211 protrudes from the side facing the base plate 400 and is received in the first clearance groove 410, so as to provide clearance for the central portion 211 of the explosion-proof valve body 210 through the first clearance groove 410. By protruding the central portion 211 along the first direction Z towards the side close to the base plate 400, not only can the compactness of the connection with the base plate 400 be ensured, but also when the external force of the single battery cell impacts the central portion 211, the side of the central portion 211 away from the electrode assembly 300 along the first direction Z can provide a buffering effect on the impact, so as to avoid the explosion-proof valve 200 from being opened by external force impact, thereby ensuring the stability of the explosion-proof valve 200.

[0051] A base plate 400 is provided between the bottom wall 110 and the electrode assembly 300 to provide support for the electrode assembly 300 on the side facing the bottom wall 110, while preventing the explosion-proof valve 200 from deforming or opening prematurely under external pressure. Additionally, the explosion-proof valve 200 guides the gas inside the housing 100 to ensure its opening efficiency.

[0052] like Figure 8As shown, in some embodiments of this application, the explosion-proof valve 200 is provided with lugs 260 on both back sides along the third direction Y. The edge of the lug 260 facing the electrode assembly 300 has a recess 261, which is recessed along the first direction Z towards the side closest to the electrode assembly 300. It should be noted that in some embodiments, the recess 261 has an annular structure to form a weak area on the lug 260, so that when the internal pressure of the battery exceeds a predetermined pressure, the weak area on the lug 260 is ruptured, allowing the gas inside the housing 100 to escape from the weak area of ​​the lug 260, thereby quickly releasing the pressure inside the housing 100.

[0053] In other embodiments, the projection of the recess 261 along the first direction Z on the side of the electrode assembly 300 facing the bottom wall 110 is at least one of a straight line, a broken line, or a polygonal structure, which can be specifically set according to the actual situation.

[0054] like Figure 10 and Figure 11 As shown, in some embodiments of this application, the single battery cell further includes a protective sheet 500 connected to the bottom wall 110. The protective sheet 500 is disposed on the side of the explosion-proof valve 200 away from the electrode assembly 300. The projection of the protective sheet 500 on the bottom wall 110 along the first direction Z covers the explosion-proof valve 200. The protective sheet 500 is provided with a plurality of vent holes 510. The vent holes 510 penetrate the protective sheet along the first direction Z to provide protection for the explosion-proof valve, thereby enhancing the stability of the fit between the explosion-proof valve 200 and the housing 100 and the strength of the explosion-proof valve 200 itself, and improving the stability of the explosion-proof valve 200 against external impacts from all directions.

[0055] Secondly, this application provides a battery pack that includes the individual battery cells in any of the above embodiments.

[0056] It is understood that the battery pack has the beneficial effects of the individual cells in any of the above embodiments, which will not be elaborated here.

[0057] In all examples shown and described herein, any specific values ​​should be interpreted as merely exemplary and not as limitations; therefore, other examples of exemplary embodiments may have different values.

[0058] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0059] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these modifications and improvements all fall within the protection scope of this application.

Claims

1. A single-cell battery having a first orientation (Z), characterized in that, include: The housing (100) includes a bottom wall (110); The top cover (600) is connected to one end of the housing (100) along the first direction (Z) and is disposed opposite to the bottom wall (110) along the first direction (Z); An explosion-proof valve (200) is provided on the bottom wall (110); An electrode assembly (300) is disposed within the housing (100); The explosion-proof valve (200) includes an explosion-proof valve body (210) and a mounting part (220), the mounting part (220) is connected to the explosion-proof valve body (210) around it, and the mounting part (220) is connected to the bottom wall (110); The explosion-proof valve body (210) has a central portion (211) and a protrusion (212). The protrusion (212) is connected around the central portion (211). The side of the protrusion (212) away from the central portion (211) is connected to the mounting portion (220). The central portion (211) is recessed along the first direction (Z) towards the side closer to the electrode assembly (300). The protrusion (212) protrudes towards the side away from the electrode assembly (300).

2. The single-cell battery according to claim 1, characterized in that, The single cell also includes a connecting part (221), the mounting part (220) is connected to the protrusion (212) through the connecting part (221), the connecting part (221) surrounds the protrusion (212), and the connecting part (221) has a weak part (222) on the side away from the electrode assembly (300).

3. The single-cell battery according to claim 2, characterized in that, The weak portion (222) is located at the edge of the connecting portion (221). The weak portion (222) has a first end (2221) and a second end (2222). The first end (2221) and the second end (2222) are respectively located on one side of the edge of the connecting portion (221), and there is a gap between the first end (2221) and the second end (2222).

4. The single-cell battery according to claim 2, characterized in that, The single cell has a second direction (X) perpendicular to the first direction (Z), and the bottom wall (110) has a third end (111) and a fourth end (112) disposed opposite to each other along the second direction (X). The explosion-proof valve (200) is located near the third end (111) or the fourth end (112); or, the bottom wall (110) is provided with two explosion-proof valves (200), one of which is located near the third end (111) and the other is located near the fourth end (112).

5. The single-cell battery according to claim 4, characterized in that, The single cell has a third direction (Y) that is perpendicular to both the first direction (Z) and the second direction (X). The explosion-proof valve (200) has a fifth end (270) and a sixth end (280) disposed opposite to each other along the second direction (X), and the difference between the distances of the fifth end (270) and the sixth end (280) to one side of the bottom wall (110) along the third direction (Y) is greater than zero.

6. The single-cell battery according to any one of claims 2 to 5, characterized in that, The explosion-proof valve (200) has a plurality of spaced grooves (230) on the side facing the electrode assembly (300). At least a portion of the groove (230) is provided in the center portion (211), and / or at least a portion of the groove (230) is provided in the protrusion (212), and / or at least a portion of the groove (230) is provided in the connecting portion (221).

7. The single-cell battery according to any one of claims 2 to 5, characterized in that, The central portion (211) has a plurality of spaced first protrusions (240) on the side facing the electrode assembly (300), and the cross-sectional area of ​​the first protrusions (240) gradually increases along the first direction (Z) from one end closer to the electrode assembly (300) to one end farther away from the electrode assembly (300). And / or, the connecting portion (221) is provided with a plurality of spaced second protrusions (250) on the side facing the electrode assembly (300), and the cross-sectional area of ​​the second protrusions (250) gradually increases along the first direction (Z) from one end closer to the electrode assembly (300) to one end farther away from the electrode assembly (300).

8. The single-cell battery according to any one of claims 1 to 5, characterized in that, The single battery also includes a base plate (400), which is disposed between the electrode assembly (300) and the bottom wall (110). The base plate (400) has a first relief groove (410) on the side facing the explosion-proof valve body (210). The middle part of the center portion (211) protrudes from the side facing the base plate (400) and is received in the first relief groove (410).

9. The single-cell battery according to claim 5, characterized in that, The explosion-proof valve (200) is provided with lugs (260) on the two opposite sides along the third direction (Y). The lugs (260) are provided with recesses (261) on the edge of the side facing the electrode assembly (300). The recesses (261) are recessed along the first direction (Z) towards the side closer to the electrode assembly (300).

10. A battery pack, characterized in that, Includes the single-cell battery as described in any one of claims 1 to 9.

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