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. The single battery has a first direction and comprises a shell, a first end cover, an electrode assembly, a bracket and an insulating film; an accommodating cavity is defined by the shell; the first end cover is connected with the shell in the first direction to cover the containing cavity, and the first end cover is provided with an anti-explosion valve. The electrode assembly is accommodated in the accommodating cavity; the support is contained in the containing cavity, the support is located between the electrode assembly and the first end cover in the first direction, the support abuts against the electrode assembly, and an anti-explosion hole corresponding to the anti-explosion valve is formed in the support in the first direction in a penetrating mode; the insulating film is contained in the containing cavity and wraps the electrode assembly, the insulating film is provided with a weak part, and the weak part is close to the support in the first direction and corresponds to the anti-explosion hole. According to the single battery provided by the invention, the weak part is arranged on the insulating film, so that the time for exhausting air from the electrode assembly to the anti-explosion valve can be shortened, and on the basis of ensuring insulation, rapid air exhausting is realized, and the air exhausting efficiency is ensured.

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] With the increasing maturity of power battery technology, it is widely used in electric vehicles and energy storage fields, so the reliability of power battery is increasingly high.

[0003] However, when the existing battery is in thermal runaway, the electrode assembly arranged on the insulating film will generate gas, which is first discharged from the periphery of the insulating film, then discharged between the insulating film and the shell, and then discharged from the shell. Because it needs to be discharged from the periphery of the insulating film first and then to the explosion-proof valve of the shell, the exhaust time is long, and there is a problem of low exhaust efficiency. 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, comprising:

[0006] a shell defining a receiving cavity;

[0007] a first end cover connected to the shell along the first direction to seal the receiving cavity, the first end cover being provided with an explosion-proof valve;

[0008] an electrode assembly received in the receiving cavity;

[0009] a bracket received in the receiving cavity, the bracket being located between the electrode assembly and the first end cover along the first direction, the bracket abutting the electrode assembly, and the bracket being provided with an explosion-proof hole corresponding to the explosion-proof valve along the first direction;

[0010] an insulating film received in the receiving cavity and wrapped around the electrode assembly, the insulating film being provided with a weak part, the weak part being located close to the bracket along the first direction and corresponding to the explosion-proof hole.

[0011] In some embodiments, the insulating film comprises a first film piece arranged close to the bracket along the first direction.

[0012] The weak part is arranged on a side of the first film piece close to the electrode assembly, and / or the weak part is arranged on a side of the first film piece close to the bracket.

[0013] In some embodiments, the first film piece has a first wall surface and a second wall surface arranged opposite to each other along the first direction.

[0014] The weakened portion is formed by local pressing or etching of the first wall surface and / or the second wall surface.

[0015] In some embodiments, the weakened portion comprises at least one first weakened segment.

[0016] The at least one first weakened segment forms a weakened area on the insulating film, and a projection of the weakened area on a plane of the first end cover along the first direction overlaps a projection of a hole wall of the explosion-proof hole on the plane of the first end cover.

[0017] In some embodiments, the weakened portion comprises one first weakened segment, and the first weakened segment has a first end and a second end.

[0018] The first weakened segment encloses the weakened area, and the first end and the second end are connected or spaced apart.

[0019] In some embodiments, the weakened portion comprises a plurality of first weakened segments, and the plurality of first weakened segments are arranged in a spaced-apart manner, and the plurality of first weakened segments enclose the weakened area.

[0020] In some embodiments, the weakened portion further comprises a second weakened segment, and the second weakened segment is located in the weakened area.

[0021] In some embodiments, the number of the second weakened segments is a plurality, and the plurality of second weakened segments are arranged in an intersecting manner to form at least one intersection point, and the plurality of second weakened segments are centrally symmetric with the intersection point.

[0022] In some embodiments, the single battery further comprises a second end cover, and the second end cover is connected to the shell to seal the accommodation cavity along the first direction, and the second end cover is arranged opposite to the first end cover along the first direction, and the second end cover is provided with a pole.

[0023] In a second aspect, the application provides a battery pack, comprising: a box body and the single battery.

[0024] Embodiments of the application have the following advantages: by arranging a weakened portion on the insulating film, the weakened portion is arranged corresponding to the explosion-proof hole, the gas generated by the electrode assembly is directly discharged to the explosion-proof valve through the weakened portion and the explosion-proof hole, without being discharged to the space between the insulating film and the shell through the periphery of the insulating film, the time for the electrode assembly to discharge to the explosion-proof valve is shortened, the gas generated inside the electrode assembly is quickly discharged through the weakened portion, and on the basis of ensuring insulation, fast discharge is realized to ensure discharge efficiency.

[0025] In order to make the above objectives, characteristics and advantages of the application more obvious and easy to understand, the following preferred embodiments are described in detail below, and the accompanying drawings are described as follows. BRIEF DESCRIPTION OF DRAWINGS

[0026] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed to be used in the embodiments will be briefly introduced as follows. It should be understood that the following drawings only show some of the embodiments of the present application, and therefore should not be considered as a limitation to the scope. For those skilled in the art, other related drawings can also be obtained without creative labor on the basis of these drawings.

[0027] Figure 1 An exploded view of a single battery is shown according to some embodiments of the present application;

[0028] Figure 2 A structural schematic diagram of an insulating film in a single battery is shown according to some embodiments of the present application;

[0029] Figure 3 An enlarged view of the A part in the first embodiment is shown; Figure 2

[0030] An enlarged view of the A part in the second embodiment is shown; Figure 4 Figure 2 An enlarged view of the A part in the third embodiment is shown;

[0031] Figure 5 Figure 2 An enlarged view of the A part in the fourth embodiment is shown;

[0032] Figure 6 An enlarged view of the A part in the fifth embodiment is shown; Figure 2

[0033] An enlarged view of the A part in the sixth embodiment is shown; Figure 7 Figure 2 An enlarged view of the A part in the seventh embodiment is shown;

[0034] Figure 8 Figure 2 An enlarged view of the A part in the eighth embodiment is shown;

[0035] Figure 9 An enlarged view of the A part in the ninth embodiment is shown; Figure 2

[0036] An enlarged view of the A part in the tenth embodiment is shown; Figure 10 Figure 2 An enlarged view of a part of a first film in a single battery is shown according to some embodiments of the present application;

[0037] Figure 11

[0038] Figure 12 ​​​​​​An enlarged view of a portion of another embodiment of a first membrane in a single battery is shown.

[0039] Figure 13 An enlarged view of a portion of another embodiment of a first membrane in a single battery is shown.

[0040] Explanation of main element symbols:

[0041] 10 - single battery; 100 - housing; 110 - accommodating cavity; 120 - first end cover; 130 - second end cover; 140 - explosion-proof valve; 150 - pole; 200 - electrode assembly; 300 - insulation film; 310 - weak portion; 320 - first membrane; 321 - first wall surface; 322 - second wall surface; 311 - first weak section; 312 - second weak section; 330 - weak region; 3111 - first end; 3112 - second end; 400 - bracket; 410 - explosion-proof hole.

[0042] X - first direction. DETAILED DESCRIPTION

[0043] Embodiments of the present application are described in detail below with reference to the attached drawing figures, wherein the same or like reference numerals are used throughout the drawings to refer to the same or like elements or elements having the same or similar functionality. The embodiments described below are illustrative examples of the present application and are not intended to be limiting.

[0044] It should 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 refer to like elements throughout the specification and no additional structures are described herewith for like reference numerals already described.

[0045] 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 meanings of the above terms in the present application can be understood according to the specific circumstances.

[0046] In addition, the terms "first", "second", etc. are used only for descriptive purposes and should not be construed as implying or suggesting relative importance or an ordered ranking of the indicated technical features. Thus, features defined with "first", "second", etc. can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "a plurality" is two or more, unless otherwise explicitly and specifically limited.

[0047] 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 template herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present application. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0048] As Figure 1 Some embodiments of the present application provide a single battery to ensure the efficiency and smoothness of exhaust, the single battery 10 has a first direction X.

[0049] The single battery 10 includes a housing 100, a first end cover 120, an electrode assembly 200, a bracket 400, and an insulating film 300.

[0050] The housing 100 defines a receiving cavity 110 having an opening, so as to accommodate the electrode assembly 200, the bracket 400 and the insulating film 300 in the receiving cavity 110 through the opening.

[0051] The first end cover 120 is connected to the housing 100 along the first direction X, and the receiving cavity 110 is sealed by the first end cover 120, so as to form a sealed receiving cavity 110 enclosed by the first end cover 120 and the housing 100, thereby protecting the electrode assembly 200, the bracket 400 and the insulating film 300.

[0052] Among them, the first end cover 120 is provided with an explosion-proof valve 140, by setting the explosion-proof valve 140 on the first end cover 120, so as 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 single battery 10 inside produces excessive pressure, the explosion-proof valve 140 will open under the action of 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.

[0053] In addition, the bracket 400 is arranged between the electrode assembly 200 and the first end cover 120 along the first direction X. Along the first direction X, the side of the bracket 400 facing the electrode assembly 200 abuts against the side of the electrode assembly 200 facing the first end cover 120, and the side of the bracket 400 facing the first end cover 120 abuts against the side of the first end cover 120 facing the electrode assembly 200, so as to limit the movement of the bracket 400 in the first direction X by the first end cover 120 and the electrode assembly 200, thereby preventing the bracket 400 from moving in the first direction X in the accommodation cavity 110, and ensuring the stability of the bracket 400 in the first direction X.

[0054] In the embodiment, the bracket 400 abuts against the electrode assembly 200, and the connection mode between the bracket 400 and the electrode assembly 200 includes at least one of lap joint, clamping, and bonding, which can be specifically set according to actual conditions.

[0055] In addition, the bracket 400 is provided with an explosion-proof hole 410 corresponding to the explosion-proof valve 140 along the first direction X. Since the bracket 400 is arranged between the electrode assembly 200 and the first end cover 120, the gas generated inside the electrode assembly 200 can flow to the first end cover 120 through the explosion-proof hole 410, so as to provide a guiding effect on the gas generated inside the electrode assembly 200 through the explosion-proof hole 410, so that the gas can impact the corresponding explosion-proof valve 140 on the first end cover 120 through the explosion-proof hole 410, thereby causing the explosion-proof valve 140 to open under the action of a preset pressure, thereby releasing the gas in the accommodation cavity 110, reducing the pressure inside the single battery 10, and preventing the single battery 10 from exploding.

[0056] The insulating film 300 is accommodated in the accommodation cavity 110 and wrapped around the electrode assembly 200, so as to form an insulating barrier between the shell 100 and the electrode assembly 200 and between the first end cover 120 and the electrode assembly 200 through the insulating film 300, thereby preventing the electrode assembly 200 from contacting the shell 100 to cause short circuit, or the electrode assembly 200 from contacting the first end cover 120 to cause short circuit.

[0057] It should be noted that in the prior art, since the single battery 10 generates gas when the electrode assembly 200 is in thermal runaway during use, when the insulating film 300 is wrapped around the electrode assembly 200, the gas generated by the electrode assembly 200 needs to break through the insulating film 300 around the insulating film 300 and then be discharged to the explosion-proof valve 140. Such a design has a long gas discharge distance, a long gas discharge time from the electrode assembly to the explosion-proof valve, and a low gas discharge efficiency.

[0058] In the embodiment, the insulation film 300 is provided with the weak part 310, the weak part 310 is arranged along the first direction X close to the support 400 and corresponds to the explosion-proof hole 410, so that when the electrode assembly 200 generates a large amount of gas by heating, and the air pressure between the insulation film 300 and the electrode assembly 200 is greater than the preset pressure resistance strength of the weak part 310, the weak part 310 can be broken through, so that the gas generated by the electrode assembly 200 can be directly discharged into the explosion-proof hole 410 through the weak part 310, and then discharged from the explosion-proof valve 140 after being discharged to the explosion-proof valve 140.

[0059] It can be understood that the air pressure of the gas discharged through the weak part 310 at the explosion-proof hole 410 gradually increases, and when the air pressure at the explosion-proof hole 410 is greater than the preset pressure of the explosion-proof valve 140, the explosion-proof valve 140 is opened under the action of the air pressure, thereby releasing the gas in the containing cavity 110 to reduce the pressure inside the single battery 10, thereby preventing the single battery 10 from exploding.

[0060] By arranging the weak part 310 on the side of the insulation film 300 close to the first end cover 120, the distance from the gas exhaust part of the insulation film 300 to the explosion-proof hole 410 is shortened, so that the time for the gas generated by the electrode assembly 200 to enter the explosion-proof valve 140 through the weak part 310 can be shortened, thereby improving the exhaust efficiency. By arranging the weak part 310 on the insulation film 300, the gas generated by the electrode assembly 200 during operation can break through the weak part 310 without affecting other areas of the insulation film 300, that is, the pressure resistance strength of the weak part 310 is less than the strength of other areas on the insulation film 300. That is, when the air pressure between the insulation film 300 and the electrode assembly 200 is greater than the pressure that the weak part 310 can withstand, the weak part 310 is opened to allow the gas to be discharged into the explosion-proof valve 140 through the weak part 310. Not only can the exhaust efficiency and stability be ensured, but also the safety of the single battery 10 can be ensured.

[0061] As shown in Figure 1 In some embodiments of the present application, the insulation film 300 includes a first film 320, and the first film 320 is arranged along the first direction X close to the support 400, that is, the first film 320 is adjacent to the side of the support 400 facing the electrode assembly 200.

[0062] The weak part 310 is arranged on the side of the first film 320 close to the electrode assembly 200, and / or the weak part 310 is arranged on the side of the first film 320 close to the support 400.

[0063] As shown in Figure 1 and Figure 11 In some embodiments, the weak part 310 is arranged on the side of the first film 320 close to the electrode assembly 200.

[0064] As shown in Figure 1 and Figure 12 In some embodiments, the weakened portion 310 is arranged on the side of the first diaphragm 320 close to the bracket 400.

[0065] As shown in Figure 1 and Figure 13 In some embodiments, the weakened portion 310 is arranged on the side of the first diaphragm 320 close to the electrode assembly 200, and the weakened portion 310 is arranged on the side of the first diaphragm 320 close to the bracket 400.

[0066] It can be understood that the thickness of the weakened portion 310 is less than the thickness of the insulating film 300. By reducing the thickness of the weakened portion 310, the weakened portion 310 can withstand a smaller air pressure than other regions of the insulating film 300 under the action of the same air pressure, so that the weakened portion 310 can be opened under the action of the air pressure, and the other regions of the insulating film 300 can remain stable, so as to ensure the insulation quality of the insulating film 300.

[0067] As shown in Figure 2 , Figure 11 , Figure 12 and Figure 13 In some embodiments of the present application, the first diaphragm 320 has a first wall surface 321 and a second wall surface 322 arranged opposite to each other along the first direction X, and the first wall surface 321 is parallel to the second wall surface 322.

[0068] The weakened portion 310 is formed by local pressing or etching of the first wall surface 321 and / or the second wall surface 322.

[0069] It can be understood that when the weakened portion 310 is arranged on the side of the first diaphragm 320 facing the first end cover 120, the weakened portion 310 is formed by local pressing or etching of the first wall surface 321.

[0070] When the weakened portion 310 is arranged on the side of the first diaphragm 320 facing the electrode assembly 200, the weakened portion 310 is formed by local pressing or etching of the second wall surface 322.

[0071] When the weakened portion 310 is arranged on both sides of the first diaphragm 320 along the first direction X, the weakened portion 310 is formed by local pressing or etching of the first wall surface 321 and the second wall surface 322.

[0072] Forming the weakened portion 310 on the first diaphragm 320 by pressing or etching not only can avoid affecting the thickness of other regions on the first diaphragm 320, but also can improve the forming efficiency and accuracy of the position of the weakened portion 310.

[0073] As shown in Figures 2 to 10As shown, in some embodiments of this application, the weak portion 310 includes at least one first weak segment 311. It is understood that the number of first weak segments 311 can be any number of one, two, or more, and can be specifically set according to the actual situation.

[0074] Among them, at least one first weak segment 311 forms a weak region 330 on the insulating film 300, that is, the first weak segment 311 is the edge part of the weak region 330.

[0075] It should be noted that if the coverage area of ​​the weak zone 330 is smaller than the coverage area of ​​the explosion-proof hole 410, that is, the total length of the first weak section 311 is small, when the gas generated by the electrode assembly 200 breaks through the first weak section 311, the opening range of the first weak section 311 is small, which will result in low efficiency of gas discharge from the weak zone 330 between the insulating film 300 and the electrode assembly 200. If the coverage area of ​​the weak zone 330 is larger than the coverage area of ​​the explosion-proof hole 410, although the total length of the first weak section 311 increases, when the gas generated by the electrode assembly 200 breaks through the first weak section 311, a portion of the opening edge of the first weak section 311 will be misaligned with the explosion-proof hole 410, that is, the frame will block part of the first weak section 311, resulting in low exhaust efficiency.

[0076] Based on this, along the first direction X, the projection of the weak area 330 on the plane where the first end cap 120 is located overlaps with the projection of the hole wall of the explosion-proof hole 410 on the plane where the first end cap 120 is located, so as to maximize the effective length of the first weak section 311 while ensuring that the first weak section 311 is not blocked by the frame, thereby improving the efficiency, smoothness and stability of the gas between the insulating film 300 and the electrode assembly 200 being discharged from the weak area 330.

[0077] like Figures 2 to 5 As shown, in some embodiments of this application, the weak portion 310 includes a first weak segment 311, which encloses and forms a weak region 330.

[0078] The first weak segment 311 has a first end 3111 and a second end 3112, and the first end 3111 and the second end 3112 are connected or spaced apart.

[0079] It is understandable that, such as Figure 2 and Figure 3As shown, in some embodiments, the first end 3111 and the second end 3112 are connected, that is, the first weak segment 311 is connected end to end to form a weak area 330 with closed edges. When the gas generated by the electrode assembly 200 breaks through the first weak segment 311, the weak area 330 can separate from the first diaphragm 320. The opening formed by the first weak segment 311 is the largest, so as to improve the exhaust efficiency. It should be noted that when the projection of the weak area 330 on the plane where the first end cover 120 is located overlaps with the projection of the hole wall of the explosion-proof hole 410 on the plane where the first end cover 120 is located, the larger the opening formed by the first weak segment 311, the better the exhaust efficiency.

[0080] It is understandable that, such as Figure 4 and Figure 5 As shown, in some embodiments, there is a gap between the first end 3111 and the second end 3112, that is, the first weak section 311 forms a weak area 330 with a connecting portion at its ends. When the gas generated by the electrode assembly 200 breaks through the first weak section 311, the first weak section 311 opens. Since there is a connecting portion between the first end 3111 and the second end 3112, the weak area 330 is connected to the first diaphragm 320 through the connecting portion to prevent the weak area 330 from detaching from the first diaphragm 320. This not only ensures the exhaust efficiency, but also prevents the weak area 330 from moving in the receiving cavity 110, ensuring the stability of the position of the weak area 330 on the first diaphragm 320.

[0081] It should be noted that the connecting part is part of the first diaphragm 320, and the thickness of the connecting part is equal to the thickness of the non-first weak segment 311 on the first diaphragm 320.

[0082] like Figures 6 to 8 As shown, in some embodiments of this application, the weak portion 310 includes multiple first weak segments 311, which are spaced apart and enclose a weak area 330. It is understood that the number of first weak segments 311 can be any number of two or more values, and can be specifically set according to the actual situation.

[0083] like Figure 6 and Figure 7 As shown, in some embodiments, the weak portion 310 includes two first weak segments 311, the ends of the two first weak segments 311 are spaced apart, and the two first weak segments 311 are centrally symmetrical about the midpoint of the weak area 330, so as to ensure that the exhaust efficiency of the two first weak segments 311 is equal when they are opened, thereby ensuring the uniformity, stability and smoothness of exhaust.

[0084] like Figure 8As shown in the drawings, in some embodiments, the weakened portion 310 comprises four first weakened sections 311, the ends of the four first weakened sections 311 are spaced apart, and the four first weakened sections 311 are centrally symmetric with the midpoint of the weakened area 330, so as to ensure that the exhaust efficiency of the four first weakened sections 311 is equal when the four first weakened sections 311 are opened, thereby ensuring the uniformity, stability and smoothness of the exhaust, and further improving the stability of the weakened area 330 on the first diaphragm 320, preventing the weakened area 330 from falling off the first diaphragm 320, and ensuring the exhaust quality.

[0085] As shown in the drawings, Figure 9 and Figure 10 In some embodiments of the present application, the weakened portion 310 further comprises a second weakened section 312, and the second weakened section 312 is located in the weakened area 330.

[0086] The second weakened section 312 is formed by local pressing or etching of the first wall surface 321 and / or the second wall surface 322. In addition, the length of the second weakened section 312 can be specifically set according to actual conditions. It can be understood that by increasing the length of the second weakened section 312, the opening range of the weakened area 330 can be increased, thereby further improving the exhaust efficiency.

[0087] In the present embodiment, the shape of the second weakened section 312 can be at least any one of a straight line, a broken line, an arc, a circle, an ellipse, a polygon, or a combination of two or more thereof.

[0088] As shown in the drawings, Figure 9 and Figure 10 In some embodiments of the present application, the number of the second weakened section 312 is multiple, and the number of the second weakened section 312 can be two or any number of two or more, which can be specifically set according to actual conditions.

[0089] The multiple second weakened sections 312 are arranged to intersect to form at least one intersection point. It can be understood that when the multiple second weakened sections 312 are spaced apart from each other, the size of the opening of the second weakened section 312 is the same as the length of the second weakened section 312 when the second weakened section 312 is opened under the action of the gas pressure, that is, the gas can be discharged from the second weakened section 312. When the two second weakened sections 312 intersect to form an intersection point, the second weakened sections 312 at the intersection point are separated from each other when the second weakened sections 312 are opened under the action of the gas pressure, so as to form a gap at the intersection point, thereby further increasing the area of the exhaust port of the weakened area 330, and further improving the exhaust efficiency.

[0090] In the present embodiment, the multiple second weakened sections 312 are centrally symmetric with the intersection point, so as to ensure that the exhaust efficiency of each part of the weakened area 330 is the same when the second weakened sections 312 are opened under the action of the gas pressure, thereby ensuring the uniformity and stability of the exhaust.

[0091] AsFigure 1 As shown, in some embodiments of the present application, the single battery 10 further comprises a second end cover 130, the second end cover 130 is connected with the shell 100 along the first direction X to cover the accommodating cavity 110, and the second end cover 130 is arranged opposite to the first end cover 120 along the first direction X, and the second end cover 130 is provided with a pole 150.

[0092] Since the insulating film generally wraps the electrode assembly 200 except the side facing the second end cover 130, when the electrode assembly 200 generates a large amount of gas due to thermal runaway, part of the gas can be discharged from the side of the second end cover 130.

[0093] If the above-mentioned thermal-electric separation scheme is adopted, i.e., the explosion-proof valve 140 and the pole 150 are not designed on the same side, part of the gas generated by the electrode assembly 200 needs to be discharged from the side of the pole 150 first, and then discharged to the side provided with the explosion-proof valve 140 through the side of the electrode assembly 200, which results in a very long distance for gas discharge and reduces the gas discharge efficiency.

[0094] In the insulating film 300 provided with the weak part 310, the gas generated inside the electrode assembly 200 can be quickly discharged from the weak part 310, which can shorten the distance for gas discharge from the side of the pole 150 to the explosion-proof valve 140.

[0095] The second end cover 130 is connected with the shell 100 and covers the accommodating cavity 110. The connection between the second end cover 130 and the shell 100 at least includes one of clamping, bonding, bolt connection, or integral connection.

[0096] In addition, the present application also provides a battery pack, which comprises a box body and the single battery 10, and the single battery 10 is installed in the box body.

[0097] In the present embodiment, the single battery 10 can be accommodated in the box body to form a battery pack. A plurality of single batteries 10 can also be first grouped into a battery module, and then the battery module is accommodated in the box body to form a battery pack.

[0098] It can be understood that the battery pack has the beneficial effects of the single battery 10 in any of the above-mentioned embodiments, which will not be repeated here.

[0099] In all the examples shown and described herein, any specific values should be interpreted as merely exemplary and not as a limitation, and thus, other examples of the example embodiments can have different values.

[0100] It should be noted that similar reference numbers and letters represent similar items in the following drawings, and thus, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0101] 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), characterized in that, The application relates to a shell (100) defining a containing cavity (110); a first end cover (120) connected with the shell (100) along a first direction (X) to seal the containing cavity (110), the first end cover (120) being provided with an explosion-proof valve (140); an electrode assembly (200) accommodated in the containing cavity (110); a bracket (400) accommodated in the containing cavity (110), the bracket (400) being located between the electrode assembly (200) and the first end cover (120) along the first direction (X), the bracket (400) being in abutment with the electrode assembly (200), and the bracket (400) being provided with an explosion-proof hole (410) corresponding to the explosion-proof valve (140) along the first direction (X); and an insulation film (300) accommodated in the containing cavity (110) and wrapped around the electrode assembly (200), the insulation film (300) being provided with a weak part (310), the weak part (310) being arranged close to the bracket (400) along the first direction (X) and corresponding to the explosion-proof hole (410). The insulation film (300) comprises a first film sheet (320) arranged close to the bracket (400) along the first direction (X). The weak part (310) is arranged on one side of the first film sheet (320) close to the electrode assembly (200) and / or on one side of the first film sheet (320) close to the bracket (400). The first film sheet (320) has a first wall surface (321) and a second wall surface (322) arranged opposite to each other along the first direction (X). The weak part (310) is formed by local pressing or etching of the first wall surface (321) and / or the second wall surface (322). The weak part (310) comprises at least one first weak section (311).

2. The cell according to claim 1, wherein At least one first weak section (311) forms a weak area (330) on the insulation film (300), and a projection of the weak area (330) on a plane where the first end cover (120) is located along the first direction (X) overlaps with a projection of a hole wall of the explosion-proof hole (410) on the plane where the first end cover (120) is located. The weak part (310) comprises one first weak section (311), and the first weak section (311) has a first end (3111) and a second end (3112).

3. The cell according to claim 2, wherein The first weak section (311) encloses the weak area (330), and the first end (3111) and the second end (3112) are connected or spaced. The weak part (310) comprises a plurality of first weak sections (311), and the plurality of first weak sections (311) are arranged in a spaced manner, and the plurality of first weak sections (311) enclose the weak area (330).

4. The cell according to claim 2, wherein The weak part (310) further comprises a second weak section (312), and the second weak section (312) is located in the weak area (330). ​ 5. The cell according to claim 4, wherein ​ ​ 6. The cell according to claim 4, wherein ​ 7. The cell according to claim 4, wherein ​ 8. The cell according to claim 7, wherein The second weak sections (312) are multiple, and the multiple second weak sections (312) are arranged to intersect to form at least one intersection point, and the multiple second weak sections (312) are centrally symmetric with the intersection point.

9. The single cell according to any one of claims 1 to 7, characterized in that, The single battery further comprises a second end cover (130), the second end cover (130) is connected with the shell (100) to cover the accommodating cavity (110) along the first direction (X), and the second end cover (130) is arranged opposite to the first end cover (120) along the first direction (X), and the second end cover (130) is provided with a pole (150).

10. A battery pack, characterized by, Comprising: A box and the single battery of any one of claims 1 to 9, wherein the single battery is installed in the box.

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