Single battery and battery pack

Abstract

The utility model provides a single battery and a battery pack, and belongs to the technical field of batteries. Each single battery has a first direction and a second direction which are intersected, and each single battery comprises a shell, a first end cover, a pole and an insulating layer; an accommodating cavity is defined by the shell; the first end cover is arranged on one side of the shell and covers the containing cavity in a sealing mode, and the first end cover is provided with an anti-explosion valve. The pole penetrates through the shell wall, deviating from the first end cover in the first direction, of the shell; the electrode assembly is accommodated in the accommodating cavity; the insulating layer is contained in the containing cavity and wraps the electrode assembly, an exhaust groove is formed in at least one of the two opposite sides of the insulating layer in the second direction, the exhaust groove extends in the first direction, and the exhaust groove is communicated with the pole and the anti-explosion valve. According to the single battery provided by the invention, the exhaust groove is formed in the insulating layer, and the exhaust groove is positioned on one side, close to the shell along the second direction, of the insulating layer, so that the exhaust groove can be prevented from being blocked, and the exhaust efficiency is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of battery, in particular to a single battery and a battery pack. BACKGROUND

[0002] In the field of power battery, how to ensure the manufacturability and safety reliability of the battery is the most important for battery manufacturing enterprises, and the reliability of the valve pressure relief of the battery is particularly crucial. In the square electrode assembly or short knife electrode assembly structure, the explosion-proof valve is often designed on the end cover of the pole post in the industry. However, with the further optimization of the safety of the electrode assembly, more and more enterprises begin to choose the scheme of thermal-electric separation.

[0003] The exhaust channel inside the single battery is prone to blockage, which affects the exhaust effect. Therefore, how to ensure the smoothness of the exhaust is a technical problem to be solved in the battery technology. CONTENT OF THE UTILITY MODEL

[0004] Therefore, the purpose of the present application is to overcome the deficiencies in the prior art and provide a single battery and a battery pack.

[0005] In a first aspect, the present application provides a single battery having a first direction and a second direction intersecting each other, comprising:

[0006] a housing defining a receiving cavity;

[0007] a first end cover arranged on one side of the housing and covering the receiving cavity, the first end cover being provided with an explosion-proof valve;

[0008] a pole post penetrating the housing wall of the housing along the first direction away from the first end cover;

[0009] an electrode assembly accommodated in the receiving cavity;

[0010] an insulation layer accommodated in the receiving cavity and wrapped outside the electrode assembly, two opposite sides of the insulation layer along the second direction being connected with the housing, at least one of the two opposite sides of the insulation layer along the second direction being provided with an exhaust groove, the exhaust groove being located on the side of the insulation layer close to the housing along the second direction, the exhaust groove extending along the first direction, and the exhaust groove being in communication with the pole post and the explosion-proof valve.

[0011] In some embodiments, the single battery has a third direction intersecting with the first direction and the second direction;

[0012] The number of the exhaust grooves is multiple, and the multiple exhaust grooves are arranged at intervals along the third direction.

[0013] In some embodiments, the insulation layer has a plurality of protrusions protruding towards the housing along the second direction and in contact with the housing, and the exhaust groove is located between two adjacent protrusions along the third direction.

[0014] In some embodiments, the insulation layer comprises a first film and a second film connected to each other.

[0015] The first film comprises a first large surface and two first side surfaces connected to the first large surface, and the two first side surfaces are oppositely arranged along the second direction.

[0016] The second film comprises a second large surface and two second side surfaces connected to the second large surface, and the two second side surfaces are oppositely arranged along the second direction.

[0017] The first side surface and the second side surface are connected along the second direction, and the first side surface is located on the side of the second side surface away from the electrode assembly, and the exhaust groove is arranged on the side of the first side surface away from the electrode assembly.

[0018] In some embodiments, the insulation layer further comprises a third film, and the first large surface and the second large surface are connected through the third film, and the third film is in abutment with the first end cover along the first direction.

[0019] In some embodiments, the first side surface and the second side surface at least partially overlap in projection along the second direction.

[0020] In some embodiments, the insulation layer has a plurality of protrusions protruding towards the housing along the second direction and in contact with the housing, and the protrusions are arc surfaces along the third direction.

[0021] The arc surfaces of two adjacent protrusions are connected, and the exhaust groove is located between two adjacent protrusions along the third direction.

[0022] In some embodiments, the first end cover is provided with a protruding portion protruding away from the electrode assembly, a concave cavity is formed on the side of the first end cover facing the electrode assembly, the explosion-proof valve is arranged in the protruding portion, and the concave cavity is in communication with the exhaust groove.

[0023] In some embodiments, the housing wall is a second end cover, the second end cover is oppositely arranged with the first end cover along the first direction, the pole is arranged through the second end cover and connected with the electrode assembly.

[0024] In a second aspect, the application provides a battery pack, comprising: a box body and the monomer battery, and the monomer battery is installed in the box body.

[0025] The embodiments of the present application have the advantages that: by wrapping the insulating layer on the electrode assembly, the insulating layer forms an insulating barrier between the electrode assembly and the shell, by providing the exhaust groove on the insulating layer, the accommodation cavity and the explosion-proof valve are communicated, so that the gas generated by the electrode assembly can be guided to the explosion-proof valve through the exhaust groove, and since the exhaust groove is located on the side of the insulating layer close to the shell in the second direction, the exhaust groove can be prevented from being blocked, on the basis of ensuring insulation, fast exhaust is realized, and the exhaust efficiency is improved.

[0026] In order to make the above objectives, characteristics and advantages of the present application more apparent and easy to understand, the following preferred embodiments are specifically described below, and the accompanying drawings are described in detail as follows. BRIEF DESCRIPTION OF DRAWINGS

[0027] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments, and it should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as a limitation on the scope, and for those skilled in the art, other related drawings can also be obtained without creative labor on the basis of these drawings.

[0028] Figure 1 An exploded view of a single battery according to some embodiments of the present application is shown;

[0029] Figure 2 A structural schematic diagram of an embodiment of a first diaphragm in a single battery according to some embodiments of the present application is shown;

[0030] Figure 3 A structural schematic diagram of a first perspective view of an insulating layer unfolded in a single battery according to some embodiments of the present application is shown;

[0031] Figure 4 A structural schematic diagram of another embodiment of a first diaphragm in a single battery according to some embodiments of the present application is shown.

[0032] Main element symbol explanation:

[0033] 10-single battery; 100-shell; 110-accommodation cavity; 120-first end cover; 121-protruding part; 130-second end cover; 140-explosion-proof valve; 150-pole; 200-electrode assembly; 300-insulating layer; 311-exhaust groove; 312-convex strip; 313-convex flange; 320-first diaphragm; 321-first large face part; 322-first side face part; 330-second diaphragm; 331-second large face part; 332-second side face part; 340-third diaphragm.

[0034] X - first direction; Y - second direction; Z - third direction. DETAILED DESCRIPTION

[0035] Embodiments of the present application are described in detail below with reference to the attached drawing figures, wherein the same or like reference numerals and characters throughout the figures denote the same or like elements or features. The embodiments described below are exemplary, and are not intended to be limiting of the present application.

[0036] It is to be noted that when an element is referred to as being "on" another element, it can be directly on the other element or intervening elements can also be present. In contrast, when an element is referred to as being "directly on" another element, there are no intervening elements present. Like reference numerals in the figures denote like elements throughout the specification.

[0037] In the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connecting", "fixing" and the like should be understood in a broad sense, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above-mentioned terms in the present application can be understood according to the specific circumstances.

[0038] In addition, the terms "first", "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "multiple" is two or more, unless otherwise explicitly specified and limited.

[0039] 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 in the description of the specification of the template is only for the purpose of describing the specific embodiments, and is not intended to limit the present application. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0040] As Figure 1 As shown in the drawings, the present application provides a single battery 10, mainly for enabling the gas generated inside the single battery 10 to be quickly and smoothly guided to the explosion-proof valve 140, so as to improve the stability and smoothness of the exhaust.

[0041] The single battery 10 has a first direction X and a second direction Y intersecting. The single battery 10 includes a shell 100, a first end cover 120, a pole 150, an electrode assembly 200, and an insulation layer 300.

[0042] The shell 100 defines a receiving cavity 110 with an opening, and the electrode assembly 200 is installed in the receiving cavity 110 through the opening, thereby providing protection and limiting the electrode assembly 200. It can be understood that the electrode assembly 200 is installed in the receiving cavity 110 through the opening and is capped at the opening by the first end cover 120, thereby housing the electrode assembly 200 in the sealed receiving cavity 110 to provide protection and fixation of the electrode assembly 200 by the shell 100 and the first end cover 120, ensuring the safety and stability of the electrode assembly 200 in the receiving cavity 110.

[0043] The first end cover 120 is arranged on one side of the shell 100 and capped on the receiving cavity 110 by the first end cover 120, so as to form a sealed receiving cavity 110 by the inner wall of the shell 100 and the side of the first end cover 120 facing the receiving cavity 110, ensuring the stability of the electrode assembly 200 in the receiving cavity 110.

[0044] The connection between the first end cover 120 and the shell 100 includes at least one of snap connection, adhesion, threaded connection, bolt connection, hinged connection, or one-piece forming.

[0045] In addition, the first end cover 120 is provided with an explosion-proof valve 140, which is arranged on the first end cover 120 to control the pressure inside the single battery 10 through the explosion-proof valve 140, thereby preventing the single battery 10 from exploding. When the pressure inside the single battery 10 is too high, the explosion-proof valve 140 will open under the action of the pressure, thereby releasing the high-pressure gas generated inside the single battery 10 to the external environment, thereby reducing the pressure inside the single battery 10, thereby effectively preventing the risk of explosion of the single battery 10.

[0046] The pole 150 is arranged in the shell wall of the shell 100 away from the first end cover 120 along the first direction X, so as to form a thermal-electric separation structure on the single battery 10, that is, the explosion-proof valve 140 and the pole 150 are not designed on the same side, so as to enhance the safety of the battery system, prevent the chain reaction caused by local thermal runaway, and reduce the risk of thermal runaway.

[0047] The insulation layer 300 is housed in the receiving cavity 110 and wrapped around the electrode assembly 200 to prevent the positive and negative electrodes of the electrode assembly 200 from contacting, avoid short circuit of the electrode assembly 200, and ensure the safety performance of the single battery 10.

[0048] The insulation layer 300 is connected to the shell 100 on both sides opposite to each other along the second direction Y, at least one side of the two sides opposite to each other along the second direction Y of the insulation layer 300 is provided with an exhaust groove 311, the exhaust groove 311 is located on the side of the insulation layer 300 close to the shell 100 along the second direction Y, and the exhaust groove 311 extends along the first direction X, the exhaust groove 311 communicates the pole column 150 and the explosion-proof valve 140, so as to guide the gas generated inside the electrode assembly 200 to the explosion-proof valve 140 through the exhaust groove 311, and ensure the uniformity of the gas pressure in each area in the containing cavity 110, thereby preventing the local bulging of the single battery 10 caused by the local overpressure.

[0049] It can be understood that in some embodiments, one side of the two sides opposite to each other along the second direction Y of the insulation layer 300 is provided with an exhaust groove 311, so as to communicate the pole column 150 and the explosion-proof valve 140 through the exhaust groove 311, so that the gas generated during the operation of the electrode assembly 200 can be guided from the pole column 150 to the explosion-proof valve 140 through the exhaust groove 311, and since the exhaust groove 311 is located on the side of the insulation layer 300 close to the shell 100 along the second direction Y, the exhaust groove 311 can be prevented from being blocked when it is out of control, thereby ensuring the smoothness and stability of the exhaust.

[0050] In addition, in some embodiments, both sides of the insulation layer 300 opposite to each other along the second direction Y are provided with exhaust grooves 311. It can be understood that by increasing the number of exhaust grooves 311, the gas guiding efficiency of the electrode assembly 200 can be further improved, thereby improving the efficiency and smoothness of the exhaust.

[0051] As shown in Figure 1 , Figure 2 and Figure 4 In some embodiments, the single battery 10 has a third direction Z intersecting with the first direction X and the second direction Y.

[0052] The number of the exhaust grooves 311 is multiple, and the multiple exhaust grooves 311 are arranged at intervals along the third direction Z. It can be understood that by increasing the number of exhaust grooves 311, the gas guiding efficiency of the electrode assembly 200 can be further improved, thereby avoiding the blocking condition and ensuring the smoothness and stability of the exhaust.

[0053] In addition, in some embodiments, the multiple exhaust grooves 311 are arranged at equal intervals along the third direction Z, so as to improve the uniformity of the gas guiding and the exhaust efficiency, thereby improving the uniformity of the gas pressure in the containing cavity 110.

[0054] As shown in Figure 2As shown, in some embodiments, the insulation layer 300 has a plurality of protrusions 312 protruding towards the housing 100 along the second direction Y and in contact with the housing 100, the plurality of protrusions 312 are arranged at intervals along the third direction Z, and the protrusions 312 extend along the first direction X, and the exhaust groove 311 is located between two adjacent protrusions 312 along the third direction Z.

[0055] In the present embodiment, along the first direction X, the length of the protrusion 312 is equal to the length of the insulation layer 300. It can be understood that by increasing the flow length of the exhaust groove 311, the exhaust groove 311 can quickly guide the gas generated by the electrode assembly 200 to the explosion-proof valve 140, thereby improving the flow and efficiency of the exhaust.

[0056] In some embodiments, the plurality of protrusions 312 are arranged at intervals along the third direction Z to form a plurality of exhaust grooves 311 arranged at intervals along the third direction Z on the insulation layer 300, thereby improving the uniformity and flow of the gas generated by the electrode assembly 200, thereby ensuring the stability of the exhaust.

[0057] It should be noted that along the second direction Y, the thickness of the protrusion 312 can be specifically set according to actual conditions. It can be understood that by increasing the thickness of the protrusion 312, the depth of the exhaust groove 311 is increased, thereby increasing the exhaust capacity of the exhaust groove 311 per unit volume, thereby effectively improving the exhaust efficiency of the exhaust groove 311. In addition, along the third direction Z, by increasing the distance between the two adjacent protrusions 312, the width of the exhaust groove 311 is increased, thereby increasing the exhaust capacity of the exhaust groove 311 per unit volume, thereby improving the exhaust efficiency of the exhaust groove 311.

[0058] As shown, in some embodiments, the insulation layer 300 includes a first film 320 and a second film 330 connected. Figure 3

[0059] Among them, the first film 320 includes a first large face 321 and two first side faces 322 connected thereto, and the two first side faces 322 are respectively arranged opposite along the second direction Y.

[0060] It should be noted that, Figure 2 The structure of the insulation layer 300 is shown in the structure diagram, from which it can be seen that along the first direction X, the length of the first side face 322 is equal to the length of the first large face 321, so that the first side face 322 and the first large face 321 can completely fit and cover the side wall of the electrode assembly 200, respectively, to ensure the insulation quality.

[0061] ​In the embodiment, the first side part 322 and the first large part 321 are integrally connected to form the first film sheet 320. By bending the connection between the first side part 322 and the first large part 321, a structure as shown in Figure 3 or Figure 4 in the drawings can be formed.

[0062] In addition, the second film sheet 330 includes a second large part 331 and two second side parts 332, and the two second side parts 332 are respectively connected to the two sides of the second large part 331 along the second direction Y.

[0063] As can be seen from Figure 2 , along the first direction X, the length of the second side part 332 is equal to the length of the second large part 331, so as to ensure that the second side part 332 and the second large part 331 can completely fit and cover the side wall of the electrode assembly 200, thereby ensuring the insulation quality.

[0064] In the embodiment, the first side part 322 and the second side part 332 are connected along the second direction Y, and the first side part 322 is located on the side of the second side part 332 away from the electrode assembly 200. The insulation layer 300 having a containing space is formed by the first film sheet 320 and the second film sheet 330, and the electrode assembly 200 is contained in the containing space, so as to wrap the insulation layer 300 outside the electrode assembly 200, thereby ensuring the safety of the electrode assembly 200.

[0065] Among them, the connection mode between the first side part 322 and the second side part 332 includes bonding or hot melt connection, so as to ensure the stability of the connection between the first side part 322 and the second side part 332, thereby ensuring the overall strength and stability of the insulation layer 300.

[0066] In the embodiment, the exhaust groove 311 is arranged on the side of the first side part 322 away from the electrode assembly 200, that is, the convex strip 312 is arranged on the side of the first side part 322 away from the electrode assembly 200.

[0067] As shown in Figure 2 , in the embodiment, the insulation layer 300 further includes a third film sheet 340, and the first film sheet 320 and the second film sheet 330 are connected through the third film sheet 340, that is, the first large part 321 and the second large part 331 are connected through the third film sheet 340. The third film sheet 340 is arranged between the first end cover 120 and the electrode assembly 200, and the side of the third film sheet 340 facing the first end cover 120 along the first direction X abuts against the edge of the first end cover 120.

[0068] In some embodiments, the first side portion 322 and the second side portion 332 at least partially overlap in projection along the second direction Y.

[0069] It is understood that in some embodiments, the first side portion 322 and the second side portion 332 partially overlap when projected along the second direction Y, so as to ensure the stability of the connection between the first side portion 322 and the second side portion 332, while reducing the width of the first side portion 322 and the second side portion 332 to reduce costs.

[0070] like Figure 1 As shown, in some embodiments, the first side portion 322 and the second side portion 332 completely overlap in projection along the second direction Y. It is understood that by increasing the overlapping area between the first side portion 322 and the second side portion 332, the connection quality between the first side portion 322 and the second side portion 332 can be improved, while also avoiding thickness differences on one side of the electrode assembly 200 along the second direction Y.

[0071] In addition, by increasing the overlapping area between the first side portion 322 and the second side portion 332, the number of protrusions 312 and exhaust grooves 311 can be effectively increased, thereby improving exhaust efficiency.

[0072] In some embodiments, an adhesive layer is provided between the first side portion 322 and the second side portion 332 to bond the first side portion 322 to the second side portion 332, thereby ensuring the stability of the connection between the first side portion 322 and the second side portion 332, and ensuring the stability of the connection between the first diaphragm 320 and the second diaphragm 330.

[0073] like Figure 4 As shown, in some embodiments, the insulating layer 300 has a plurality of flanges 313, which protrude along the second direction Y toward the direction close to the housing 100 and are in contact with the housing 100. Both sides of the flange 313 along the third direction Z are arc surfaces, which are quarter-circular arc surfaces, and the flange 313 extends along the first direction X.

[0074] In this embodiment, along the first direction X, the length of the flange 313 along the first direction is equal to the length of the insulating layer 300.

[0075] Among them, the arc surfaces of two adjacent flanges 313 are connected, and the exhaust groove 311 is located between two adjacent flanges 313 along the third direction Z.

[0076] In some embodiments, a plurality of flanges 313 are connected sequentially along the third direction Z to form a plurality of exhaust grooves 311 arranged along the third direction Z on the insulating layer 300, thereby improving the uniformity and smoothness of the gas flow generated by the electrode assembly 200, thereby ensuring the stability of the exhaust.

[0077] It should be noted that the height of the flange 313 along the second direction Y can be specifically set according to the actual situation. It can be understood that by increasing the height of the flange 313, the depth of the exhaust groove 311 is increased, thereby increasing the exhaust volume per unit volume of the exhaust groove 311, thus effectively improving the exhaust efficiency of the exhaust groove 311. Additionally, by increasing the radius of the center of the arc surface, the cross-sectional area of ​​the exhaust groove 311 is increased, thereby increasing the exhaust volume per unit volume of the exhaust groove 311 and improving the exhaust efficiency of the exhaust groove 311.

[0078] like Figure 1 As shown, in this embodiment, the first end cap 120 is provided with a protrusion 121. The protrusion 121 is provided on the side of the first end cap 120 away from the electrode assembly 200, that is, the protrusion 121 protrudes in the direction away from the electrode assembly 200, and a cavity is formed on the side of the first end cap 120 facing the electrode assembly 200. The explosion-proof valve 140 is provided on the protrusion 121. The cavity is connected to the exhaust groove 311 so that the gas generated by the electrode assembly 200 in the receiving cavity 110 can be guided to the cavity through the exhaust groove 311.

[0079] The concave cavity and the side of the electrode assembly 200 facing the first end cover 120 form an exhaust space, which guides the gas generated inside the electrode assembly 200 through the concave cavity, so that the gas can impact the explosion-proof valve 140 provided on the first end cover 120 to achieve rapid exhaust and ensure exhaust efficiency. This allows the explosion-proof valve 140 to open under a preset pressure, thereby releasing the gas in the receiving cavity 110, reducing the pressure inside the single cell 10, and thus preventing the single cell 10 from exploding.

[0080] The protrusion 121 separates the electrode assembly 200 from the explosion-proof valve 140, so that the electrode assembly 200 will not directly contact the explosion-proof valve 140. This avoids the electrode assembly 200 being sucked onto the corresponding position of the explosion-proof valve 140 due to the internal and external pressure difference after the explosion-proof valve 140 is opened, thus preventing the explosion-proof valve 140 from being blocked.

[0081] It should be noted that the number of protrusions 121 can be any number of two or more values, and can be set according to the actual situation.

[0082] Since the third diaphragm 340 is disposed on the side of the electrode assembly 200 facing the first end cap 120, and the protrusion 121 is disposed on the side of the first end cap 120 away from the electrode assembly 200, that is, the protrusion 121 protrudes in the direction away from the electrode assembly 200, forming a cavity on the side of the first end cap 120 facing the electrode assembly 200, it can be understood that the side of the third diaphragm 340 facing the first end cap 120 abuts against the side of the first end cap 120 facing the electrode assembly 200, that is, the side of the third diaphragm 340 facing the first end cap 120 and the inner wall of the cavity enclose the cavity to form an exhaust space.

[0083] like Figure 1 As shown, in some embodiments, the shell wall is a second end cap 130, which is disposed opposite to the first end cap 120 along the first direction X, so as to form a sealed receiving cavity 110 by connecting the first end cap 120, the second end cap 130 and the shell 100, so as to ensure the stability of the electrode assembly 200 in the receiving cavity 110.

[0084] The electrode post 150 passes through the second end cap 130 and is connected to the electrode assembly 200 so as to connect the electrode assembly 200 to the external carrier through the electrode post 150.

[0085] The connection method between the second end cap 130 and the housing 100 includes at least one of the following: snap-fit, adhesive, bolt connection or integral connection.

[0086] This application provides a battery pack, which includes a housing and the aforementioned individual battery 10, wherein the individual battery 10 is installed in the housing.

[0087] In this embodiment, individual battery cells 10 can be housed in a casing to form a battery pack. Alternatively, multiple individual battery cells 10 can be grouped into a battery module, and then the battery module can be housed in a casing to form a battery pack.

[0088] It is understood that the battery pack has the beneficial effects of the single cell 10 described in any of the above embodiments, which will not be elaborated here.

[0089] 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.

[0090] 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.

[0091] The above embodiments only express several implementation ways of the present application, and the description is more specific and detailed, but it should not be understood as a limitation to the scope of the present application. It should be pointed out that, for ordinary skilled in the art, without departing from the concept of the present application, several modifications and improvements can be made, which all belong to the protection scope of the present application.

Claims

1. A single cell having a first direction (X) and a second direction (Y) intersecting, characterized in that, The single battery (10) has a third direction (Z) intersecting with the first direction (X) and the second direction (Y) two by two. The number of the exhaust grooves (311) is multiple, and multiple exhaust grooves (311) are arranged at intervals along the third direction (Z). The insulation layer (300) has multiple convex strips (312), the convex strips (312) are convex in the direction close to the shell (100) along the second direction (Y) and are in contact with the shell (100), and the exhaust grooves (311) are located between two adjacent convex strips (312) along the third direction (Z). The insulation layer (300) includes a first diaphragm (320) and a second diaphragm (330) connected in series. The first diaphragm (320) includes a first large surface part (321) and two first side surface parts (322) connected thereto, and the two first side surface parts (322) are arranged opposite to each other along the second direction (Y) respectively. The second diaphragm (330) includes a second large surface part (331) and two second side surface parts (332) connected thereto, and the two second side surface parts (332) are arranged opposite to each other along the second direction (Y) respectively.

2. The single cell (10) according to claim 1, characterized in that The first side surface part (322) is connected to the second side surface part (332) along the second direction (Y), the first side surface part (322) is located on the side of the second side surface part (332) away from the electrode assembly (200), and the exhaust groove (311) is arranged on the side of the first side surface part (322) away from the electrode assembly (200). The insulation layer (300) further includes a third diaphragm (340), the first large surface part (321) and the second large surface part (331) are connected through the third diaphragm (340), and the third diaphragm (340) is in abutment with the first end cover (120) along the first direction (X).

3. The single cell (10) according to claim 2, characterized in that ​ 4. The single cell (10) according to claim 1, characterized in that ​ ​ ​ ​ 5. The single cell (10) according to claim 4, characterized in that ​ 6. The single cell (10) according to claim 4, characterized in that The first side portion (322) and the second side portion (332) at least partially overlap in the projection in the second direction (Y).

7. The single cell (10) according to claim 2, characterized in that The insulation layer (300) has a plurality of flanges (313) which protrude in the direction close to the shell (100) in the second direction (Y) and are in contact with the shell (100), and both sides of the flange (313) in the third direction (Z) are circular arc surfaces; The circular arc surfaces of two adjacent flanges (313) are connected, and the exhaust groove (311) is located between the two adjacent flanges (313) in the third direction (Z).

8. The single cell (10) according to any one of claims 1 to 7, characterized in that The first end cover (120) is provided with a protruding portion (121) which protrudes in the direction away from the electrode assembly (200), a concave cavity is formed on the side of the first end cover (120) facing the electrode assembly (200), and the explosion-proof valve (140) is arranged on the protruding portion (121), and the concave cavity is in communication with the exhaust groove (311).

9. The single cell (10) according to any one of claims 1 to 7, characterized in that The shell wall is a second end cover (130), the second end cover (130) is arranged opposite to the first end cover (120) in the first direction (X), the pole (150) is arranged in the second end cover (130) and is connected with the electrode assembly (200).

10. A battery pack, characterized by, The application relates to a battery pack (1) comprising: a housing and a single battery cell (10) according to any one of claims 1 to 9.

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