Battery pack and electrical device

Abstract

A battery pack (100) and an electrical device (200). The battery pack (100) comprises a battery cell assembly (20), a housing (10a), a front cover (10b), and an elastic member (30); the battery cell assembly (20) is arranged within the housing (10a); the front cover (10b) is connected to the housing (10a); the elastic member (30) and the battery cell assembly (20) are arranged along a first direction (X); in the first direction (X), one side of the elastic member (30) is connected to the housing (10a), and the other side is connected to the battery cell assembly (20); the housing (10a) comprises a top wall (11) and a bottom wall (12) arranged along a second direction (Y); the top wall (11) is provided with a first extending part (111), and the first extending part (111) comprises a first extending connection part (112) connected to the front cover (10b); the bottom wall (12) is provided with a second extending part (121), and the second extending part (121) comprises a second extending connection part (122) connected to the front cover (10b); in the first direction (X), the length (D2) of the second extending connection part (122) is less than the length (D1) of the first extending connection part (112); and the first direction (X) is perpendicular to the second direction (Y). Due to the length (D2) of the second extending connection part (122) being less than the length (D1) of the first extending connection part (112), the bottom wall (12) is more easily pushed open by the elastic member (30), which acts as a buffer against pressure of the battery cell assembly (20), reducing the risk of a pressure-inducted explosion of the battery cell assembly (20), and improving the safety of the battery pack (100).

Description

Battery packs and electrical equipment Technical Field

[0001] The present application relates to the field of energy storage technology, and in particular to a battery pack and electrical equipment. Background Art

[0002] Currently, battery packs are widely used in drones, electric vehicles, smart energy storage devices, and other fields. During use, battery packs tend to swell and require pressure relief.

[0003] Summary of the Invention

[0004] In view of this, it is necessary to provide a battery pack and electrical equipment that are conducive to relieving pressure in the battery module and improving safety.

[0005] Embodiments of the present application provide a battery pack comprising a cell assembly, a housing, a front cover, and an elastic member. The cell assembly is disposed within the housing. The front cover is connected to the housing. The elastic member and the cell assembly are arranged along a first direction. Along the first direction, one side of the elastic member is connected to the housing, and the other side is connected to the cell assembly. The housing includes a top wall and a bottom wall arranged along a second direction. The top wall is provided with a first extension, which includes a first extension connection portion connected to the front cover. The bottom wall is provided with a second extension, which includes a second extension connection portion connected to the front cover. Along the first direction, the length of the second extension connection portion is shorter than the length of the first extension connection portion. The first direction is perpendicular to the second direction. When the cell assembly expands, an expansion force acts on the elastic member, which in turn applies the expansion force to the housing. Over time, as the cell assembly continues to expand and the elastic member is compressed to its limit, the second extension connection portion is shorter than the first extension connection portion, making it easier for the elastic member to push open the bottom wall, thereby buffering the pressure of the cell assembly, reducing the risk of a pressure explosion in the cell assembly, and improving the safety of the battery pack.

[0006] In one or more of the above optional embodiments, the first extension portion is firmly connected to the front cover, which helps the elastic member to break open the bottom wall.

[0007] In one or more of the above optional embodiments, the device further includes a circuit board, which is disposed on the front cover. A first component is disposed on the side of the circuit board facing the elastic member. Along the second direction, the distance from the first component to the top wall is L1, and the distance from the first component to the bottom wall is L2, where L1 is less than L2. By placing the first component closer to the top wall, the risk of damage to the first component is reduced when the elastic member breaks through the bottom wall and the battery cell assembly breaks through the bottom wall.

[0008] In one or more optional embodiments above, along the second direction, the distance between the bottom wall and the top wall is L0, and L1 is less than 1 / 4 L0, further reducing the risk of the battery cell assembly contacting the first component and causing damage to the first component.

[0009] In one or more of the above optional embodiments, along the first direction, the first component protrudes from the circuit board more than other components.

[0010] In one or more optional embodiments above, the first extension portion includes a first bending portion, the first bending portion is connected to the first extension connection portion, and the elastic member abuts against the first bending portion, which is beneficial to increase the connection strength between the elastic member and the shell.

[0011] In one or more optional embodiments above, the second extension portion includes a second bent portion connected to the second extension connection portion. The elastic member abuts against the second bent portion, which is beneficial to increase the connection strength between the elastic member and the housing.

[0012] In one or more optional embodiments above, the elastic member includes a base, a buffer portion, and a connecting portion, wherein the base is connected to the battery cell assembly, the buffer portion is connected to the connecting portion and the base, and the connecting portion is fixed to the housing.

[0013] In one or more of the above optional embodiments, the buffer portion includes a first buffer portion connected to one side of the base portion.

[0014] In one or more optional embodiments above, the buffer portion includes a first buffer portion and a second buffer portion. Along the second direction, the first buffer portion and the second buffer portion are arranged opposite to each other, the first buffer portion is connected to one side of the base, and the second buffer portion is connected to the other side of the base.

[0015] In one or more optional embodiments above, the connecting portion includes a first connecting portion, the elastic member includes a third bending portion, and the third bending portion abuts against the first bending portion, which is beneficial to increase the connection strength between the elastic member and the shell.

[0016] In one or more optional embodiments above, the connecting portion includes a second connecting portion, the first connecting portion and the second connecting portion are arranged opposite to each other along the second direction, and the elastic member includes a fourth bent portion, which abuts against the second bent portion, thereby increasing the connection strength between the elastic member and the housing.

[0017] In one or more optional embodiments above, the top wall is provided with a first fixing portion, the first connecting portion is fixed to the first fixing portion, and along the first direction, a projection of the first fixing portion overlaps with a projection of the first connecting portion.

[0018] In one or more optional embodiments above, the bottom wall is provided with a second fixing portion, and the second connecting portion is fixed to the second fixing portion. Along the first direction, a projection of the second fixing portion overlaps with a projection of the second connecting portion.

[0019] In one or more of the above optional embodiments, the housing includes a first side wall and a second side wall, the first side wall and the second side wall being arranged along a third direction. The first side wall is fixedly connected to the front cover. The second side wall is fixedly connected to the front cover. The first side wall is provided with a third fixing portion, to which the first and second connecting portions are fixed, thereby facilitating uniform force and deformation of the elastic member. Alternatively, the second side wall is provided with a fourth fixing portion, to which the first and second connecting portions are fixed, thereby facilitating uniform force and deformation of the elastic member.

[0020] In one or more of the above optional embodiments, the first extension portion and the second extension portion are located inside the front cover, which facilitates the connection between the front cover and the housing.

[0021] In one or more of the above optional embodiments, the housing includes a rear wall connected to the top wall and the bottom wall. Along a first direction, the battery cell assembly is located between the elastic member and the rear wall, and the elastic member has a stiffness less than that of the rear wall. When the battery cell assembly expands, the elastic member deforms before the rear wall, providing space for the battery cell assembly to expand.

[0022] In one or more of the above optional embodiments, the battery cell assembly includes a battery cell unit, the battery cell unit includes a battery cell, the battery cell includes a battery cell housing, an electrode assembly, and an electrode terminal, the battery cell housing includes a main body, the electrode assembly is disposed in the main body, and the electrode terminal is connected to the electrode assembly and extends out of the battery cell housing. The top wall is provided with two first limiting portions, and the two first limiting portions are arranged along the third direction. The main body of each battery cell unit is disposed between the two first limiting portions. The movement of the battery cell assembly is guided by the two first limiting portions.

[0023] In one or more of the above optional embodiments, the bottom wall is provided with two second limiting portions, the two second limiting portions being arranged along the third direction. The main body of each battery cell unit is provided between the two second limiting portions. The two second limiting portions guide the movement of the battery cell assembly.

[0024] In one or more of the above optional embodiments, the first component includes a fuse device.

[0025] In one or more of the above optional embodiments, the second extension portion is directly connected to the inner surface of the front cover, which helps the bottom wall to be more easily opened by the elastic member.

[0026] In one or more of the above optional embodiments, the strength of the top wall is greater than the strength of the bottom wall, which is conducive to the battery cell assembly rushing out from the side where the bottom wall is located, and is conducive to further improving the safety of the battery pack.

[0027] In one or more optional embodiments above, the battery pack includes a first buffer member, which is arranged between the base and the first battery cell unit. The hardness of the first buffer member is less than that of the base, reducing damage to the first battery cell unit caused by the base.

[0028] In one or more optional embodiments above, the battery pack includes a second buffer, which is arranged between the second battery cell unit and the rear wall. The hardness of the second buffer is less than that of the rear wall, reducing damage to the second battery cell unit caused by the rear wall.

[0029] In one or more optional embodiments above, the battery pack includes a first conductive member. Along the second direction, a first gap is defined between the base and the housing. One end of the first conductive member is connected to the battery cell assembly, and the other end passes through the first gap.

[0030] In one or more of the above optional embodiments, the first conductive member is configured to move with the elastic member, which can reduce pulling on the first conductive member, reduce the risk of the first conductive member being broken, and improve the safety of the battery pack.

[0031] In one or more optional embodiments above, the battery pack includes a second conductive member, a second gap is defined between the base and the shell, one end of the second conductive member is connected to the battery cell assembly, and the other end passes through the second gap.

[0032] In one or more of the above optional embodiments, the second conductive member and the elastic member are separately provided, which is beneficial to reduce pulling on the second conductive member, reduce the risk of the second conductive member being broken, and improve the safety of the battery pack.

[0033] In one or more of the above optional embodiments, the connecting portion is provided with a flange, which is formed by folding the connecting portion in the second direction away from the buffer portion. Along the first direction, the flange is located between the connecting portion and the base. The flange can reduce the risk of the connecting portion cutting the wiring harness.

[0034] In one or more of the above optional embodiments, along the first direction, the projection of the flange does not overlap with the projection of the buffer portion, thereby reducing the impact on the deformation area of ​​the buffer portion.

[0035] An embodiment of the present application provides a battery pack comprising a cell assembly, a housing, a front cover, and an elastic member. The cell assembly is disposed within the housing. The front cover is connected to the housing. The elastic member and the cell assembly are arranged along a first direction. Along the first direction, one side of the elastic member is connected to the housing, and the other side is connected to the cell assembly. The housing comprises a top wall and a bottom wall arranged along a second direction. The top wall is provided with a first extension, which includes a first extension connection portion connected to the front cover. The bottom wall is provided with a second extension, which includes a second extension connection portion connected to the front cover. The stiffness of the first extension is greater than the stiffness of the second extension. When the cell assembly expands, the expansion force acts on the elastic member, which in turn applies the expansion force to the housing. As time passes, the cell assembly continues to expand. After the elastic member is compressed to its limit, the first extension has a greater stiffness than the second extension, which makes it easier for the elastic member to push open the bottom wall, thereby buffering the pressure of the cell assembly, reducing the risk of pressure explosion of the cell assembly, and improving the safety of the battery pack.

[0036] In one or more of the above optional embodiments, the first extension portion is firmly connected to the front cover, which helps the elastic member to break open the bottom wall.

[0037] In one or more of the above optional embodiments, the device further includes a circuit board, which is disposed on the front cover. A first component is disposed on the side of the circuit board facing the elastic member. Along the second direction, the distance from the first component to the top wall is L1, and the distance from the first component to the bottom wall is L2, where L1 is less than L2. By placing the first component closer to the top wall, the risk of damage to the first component is reduced when the elastic member breaks through the bottom wall and the battery cell assembly breaks through the bottom wall.

[0038] In one or more optional embodiments above, along the second direction, the distance between the bottom wall and the top wall is L0, and L1 is less than 1 / 4 L0, further reducing the risk of the battery cell assembly contacting the first component and causing damage to the first component.

[0039] In one or more of the above optional embodiments, along the first direction, the first component protrudes from the circuit board more than other components.

[0040] In one or more optional embodiments above, the shell includes a first bending portion, the first bending portion is connected to the first extension portion, and the elastic member abuts against the first bending portion, which is beneficial to increase the connection strength between the elastic member and the shell.

[0041] In one or more optional embodiments above, the housing includes a second bent portion connected to the second extending portion, and the elastic member abuts against the second bent portion, which is beneficial to increase the connection strength between the elastic member and the housing.

[0042] In one or more optional embodiments above, the elastic member includes a base, a buffer portion, and a connecting portion, wherein the base is connected to the battery cell assembly, the buffer portion is connected to the connecting portion and the base, and the connecting portion is fixed to the housing.

[0043] In one or more of the above optional embodiments, the buffer portion includes a first buffer portion connected to one side of the base portion.

[0044] In one or more optional embodiments above, the buffer portion includes a first buffer portion and a second buffer portion. Along the second direction, the first buffer portion and the second buffer portion are arranged opposite to each other, the first buffer portion is connected to one side of the base, and the second buffer portion is connected to the other side of the base.

[0045] In one or more optional embodiments above, the connecting portion includes a first connecting portion, the elastic member includes a third bending portion, and the third bending portion abuts against the first bending portion, which is beneficial to increase the connection strength between the elastic member and the shell.

[0046] In one or more optional embodiments above, the connecting portion includes a second connecting portion, the first connecting portion and the second connecting portion are arranged opposite to each other along the second direction, and the elastic member includes a fourth bent portion, which abuts against the second bent portion, thereby increasing the connection strength between the elastic member and the housing.

[0047] In one or more optional embodiments above, the top wall is provided with a first fixing portion, the first connecting portion is fixed to the first fixing portion, and along the first direction, a projection of the first fixing portion overlaps with a projection of the first connecting portion.

[0048] In one or more optional embodiments above, the bottom wall is provided with a second fixing portion, and the second connecting portion is fixed to the second fixing portion. Along the first direction, a projection of the second fixing portion overlaps with a projection of the second connecting portion.

[0049] In one or more of the above optional embodiments, the housing includes a first side wall, the first side wall connecting the bottom wall and the top wall, and the first side wall fixedly connected to the front cover. The first side wall is provided with a third fixing portion, and the first connecting portion and the second connecting portion are fixed to the third fixing portion, thereby facilitating uniform stress and deformation of the elastic member.

[0050] In one or more of the above optional embodiments, the housing includes a second side wall fixedly connected to the front cover. The second side wall connects the top wall and the bottom wall. The second side wall is provided with a fourth fixing portion, and the first and second connecting portions are fixed to the fourth fixing portion, thereby facilitating uniform stress and deformation of the elastic member.

[0051] In one or more of the above optional embodiments, the first extension portion and the second extension portion are located inside the front cover, which facilitates the connection between the front cover and the housing.

[0052] In one or more of the above optional embodiments, the housing includes a rear wall connected to the top wall and the bottom wall. Along a first direction, the battery cell assembly is located between the elastic member and the rear wall, and the elastic member has a stiffness less than that of the rear wall. When the battery cell assembly expands, the elastic member deforms before the rear wall, providing space for the battery cell assembly to expand.

[0053] In one or more of the above optional embodiments, the battery cell assembly includes a battery cell unit, the battery cell unit includes a battery cell, the battery cell includes a battery cell housing, an electrode assembly, and an electrode terminal, the battery cell housing includes a main body, the electrode assembly is disposed in the main body, and the electrode terminal is connected to the electrode assembly and extends out of the battery cell housing. The top wall is provided with two first limiting portions, and the two first limiting portions are arranged along the third direction. The main body of each battery cell unit is disposed between the two first limiting portions. The movement of the battery cell assembly is guided by the two first limiting portions.

[0054] In one or more of the above optional embodiments, the bottom wall is provided with two second limiting portions, the two second limiting portions being arranged along the third direction. The main body of each battery cell unit is provided between the two second limiting portions. The two second limiting portions guide the movement of the battery cell assembly.

[0055] In one or more of the above optional embodiments, the first component includes a fuse device.

[0056] In one or more of the above optional embodiments, the strength of the top wall is greater than the strength of the bottom wall, which is conducive to the battery cell assembly rushing out from the side where the bottom wall is located, and is conducive to further improving the safety of the battery pack.

[0057] In one or more optional embodiments above, the battery pack includes a first buffer member, which is arranged between the base and the first battery cell unit. The hardness of the first buffer member is less than that of the base, reducing damage to the first battery cell unit caused by the base.

[0058] In one or more optional embodiments above, the battery pack includes a second buffer, which is arranged between the second battery cell unit and the rear wall. The hardness of the second buffer is less than that of the rear wall, reducing damage to the second battery cell unit caused by the rear wall.

[0059] In one or more optional embodiments above, the battery pack includes a first conductive member. Along the second direction, a first gap is defined between the base and the housing. One end of the first conductive member is connected to the battery cell assembly, and the other end passes through the first gap.

[0060] In one or more of the above optional embodiments, the first conductive member is configured to move with the elastic member, which can reduce pulling on the first conductive member, reduce the risk of the first conductive member being broken, and improve the safety of the battery pack.

[0061] In one or more optional embodiments above, the battery pack includes a second conductive member, a second gap is defined between the base and the shell, one end of the second conductive member is connected to the battery cell assembly, and the other end passes through the second gap.

[0062] In one or more of the above optional embodiments, the second conductive member and the elastic member are separately provided, which is beneficial to reduce pulling on the second conductive member, reduce the risk of the second conductive member being broken, and improve the safety of the battery pack.

[0063] In one or more of the above optional embodiments, the connecting portion is provided with a flange, which is formed by folding the connecting portion in the second direction away from the buffer portion. Along the first direction, the flange is located between the connecting portion and the base. The flange can reduce the risk of the connecting portion cutting the wiring harness.

[0064] In one or more of the above optional embodiments, along the first direction, the projection of the flange does not overlap with the projection of the buffer portion, thereby reducing the impact on the deformation area of ​​the buffer portion.

[0065] An embodiment of the present application provides an electrical device, comprising the battery pack in any one of the above embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0066] FIG1 is a schematic structural diagram of a battery pack in some embodiments.

[0067] FIG. 2 shows an exploded schematic diagram of a battery pack in some embodiments.

[0068] FIG3 is a schematic diagram showing a partial structure of a battery pack in some embodiments.

[0069] FIG4 is a schematic diagram showing a partial structure of a battery pack in some embodiments.

[0070] FIG5 is an enlarged schematic diagram showing a portion of the structure of the battery pack in FIG4 .

[0071] FIG6 is an enlarged schematic diagram showing a portion of the structure of the battery pack in FIG4 .

[0072] FIG7 is a schematic structural diagram of a portion of a housing and an elastic member in some embodiments.

[0073] FIG8 is a schematic structural diagram of an elastic member in some embodiments.

[0074] FIG9 is a schematic structural diagram of the top wall in some embodiments.

[0075] FIG10 is a schematic structural diagram of the top wall from another perspective in some embodiments.

[0076] FIG. 11 is an enlarged schematic diagram of a portion of the top wall in FIG. 10 .

[0077] FIG12 is a schematic structural diagram of a portion of a housing in some embodiments.

[0078] FIG13 is a schematic structural diagram of the bottom wall in some embodiments.

[0079] FIG. 14 is an enlarged schematic diagram of a portion of the bottom wall in FIG. 13 .

[0080] FIG15 is a schematic diagram showing a partial structure of a battery pack in some embodiments.

[0081] FIG16 is a schematic structural diagram of a front cover and a circuit board in some embodiments.

[0082] FIG17 is a schematic diagram showing the structure of a circuit board in some embodiments.

[0083] FIG18 is a schematic structural diagram of a circuit board from another perspective in some embodiments.

[0084] FIG19 is a schematic structural diagram of a circuit board and a housing in some embodiments.

[0085] FIG20 is a schematic diagram showing a partial structure of a battery pack in some embodiments.

[0086] FIG21 shows a schematic structural diagram of a battery cell in some embodiments.

[0087] FIG22 shows an exploded schematic diagram of the battery cell in FIG21 .

[0088] FIG23 shows a schematic structural diagram of a battery cell unit in some embodiments.

[0089] FIG24 shows a schematic structural diagram of a battery cell unit from another perspective in some embodiments.

[0090] FIG25 shows a schematic structural diagram of a battery cell unit from another perspective in some embodiments.

[0091] FIG26 shows a schematic structural diagram of some battery cell units in some embodiments.

[0092] FIG27 is a schematic diagram showing the structure of some battery cell units in some embodiments.

[0093] FIG28 shows a schematic structural diagram of a battery cell unit from another perspective in some embodiments.

[0094] FIG29 shows a schematic structural diagram of electrical equipment in some embodiments.

[0095] Description of main component symbols:

[0096] Battery Pack 100

[0097] Housing 10

[0098] Housing 10a

[0099] Front cover 10b

[0100] Second hole 101b

[0101] Top wall 11

[0102] First extension portion 111

[0103] First hole 1111

[0104] First extending connection portion 112

[0105] First bending portion 113

[0106] First fixing portion 11a

[0107] First limiting portion 11b

[0108] Bottom wall 12

[0109] The second extension portion 121

[0110] The second extending connection portion 122

[0111] Second bending portion 123

[0112] Second fixing portion 12a

[0113] The second limiting portion 12b

[0114] First side wall 13

[0115] First fixing member 131

[0116] The third fixing portion 13a

[0117] Second side wall 14

[0118] Fourth fixing portion 14a

[0119] Second fixing member 141

[0120] Back wall 15

[0121] Cover 16

[0122] Battery cell assembly 20

[0123] Battery cell unit 20a

[0124] The first battery cell unit 201

[0125] The second battery cell unit 202

[0126] Battery Cell 21

[0127] Cell case 21a

[0128] Main body 211

[0129] First wall 211c

[0130] Second wall 211d

[0131] First shell 2111

[0132] First recess 2111a

[0133] Second housing 2112

[0134] Second recess 2112a

[0135] First extended edge 2113

[0136] Second extended edge 2114

[0137] Sealing portion 212

[0138] First sealing portion 212a

[0139] First sealing connection part 2121

[0140] First sealing bend portion 2122

[0141] Second sealing portion 212b

[0142] Electrode assembly 21b

[0143] Electrode terminal 21c

[0144] Bracket 22

[0145] First bracket 22a

[0146] Second bracket 22b

[0147] First connecting portion 221

[0148] First side portion 222

[0149] First side extension 224

[0150] Second connecting portion 226

[0151] Projection 227

[0152] Accommodation groove 227a

[0153] Gap 228

[0154] Elastic member 30

[0155] First gap 301

[0156] Second gap 302

[0157] base 31

[0158] Buffer portion 32

[0159] First buffer portion 321

[0160] Section 1, 321a

[0161] Section 2, 321b

[0162] Second buffer portion 322

[0163] Section 322a

[0164] Section 4, 322b

[0165] Connecting portion 33

[0166] First connection portion 331

[0167] Second connecting portion 332

[0168] Flanging 333

[0169] The third bent portion 34

[0170] Fourth bending portion 35

[0171] Circuit board 40

[0172] First component 41

[0173] First conductive member 50

[0174] The second conductive member 60

[0175] Sampling piece 70

[0176] Fasteners 101

[0177] First connection end 102

[0178] Second connection end 103

[0179] Wire 104

[0180] First insulating sheet 110

[0181] First buffer member 120

[0182] Second buffer member 130

[0183] Electrical equipment 200

[0184] First direction X

[0185] Second direction Y

[0186] The third direction Z

[0187] The following specific embodiments will further illustrate the present application in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION

[0188] The technical solutions in the embodiments of the present application will be described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments.

[0189] It should be noted that when an element is considered to be "connected" to another element, it may be directly connected to the other element or there may be a centrally disposed element. When an element is considered to be "disposed" or "provided on" another element, it may be directly disposed on the other element or there may be a centrally disposed element.

[0190] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application pertains. The terms used herein in the specification of this application are for the purpose of describing specific embodiments only and are not intended to limit this application. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0191] It should be understood that, considering the factors of actual processing tolerance, the term "perpendicular" in the technical solution of this application is used to describe the ideal state between two components. In the actual production or use state, there may be a state that is approximately perpendicular between the two components. For example, in combination with the numerical description, perpendicularity can refer to the angle between two straight lines being between 90°±10°, perpendicularity can also refer to the dihedral angle between two planes being between 90°±10°, and perpendicularity can also refer to the angle between a straight line and a plane being between 90°±10°. The two components described as "perpendicular" may not be absolute straight lines or planes, but may be roughly straight lines or planes. From a macroscopic point of view, the components can be considered as "straight lines" or "planes" if the overall extension direction is a straight line or a plane.

[0192] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application pertains. The terms used herein in the specification of this application are for the purpose of describing specific embodiments only and are not intended to limit this application.

[0193] The terms "left", "right", "top", "bottom", "front", "back" and similar expressions used herein are for illustrative purposes only and are not intended to limit the present application.

[0194] Unless otherwise defined, the term "plurality" herein, when used to describe the number of components, specifically means that the number of the components is two or more.

[0195] In the first direction X, it includes the first direction X and the direction opposite to the first direction X, in the second direction Y, it includes the second direction Y and the direction opposite to the second direction Y, and in the third direction Z, it includes the third direction Z and the direction opposite to the third direction Z.

[0196] For the convenience of description, some electrode terminals are not shown in a bent state in the drawings.

[0197] Embodiments of the present application provide a battery pack comprising a cell assembly, a housing, a front cover, and an elastic member. The cell assembly is disposed within the housing. The front cover is connected to the housing. The elastic member and the cell assembly are arranged along a first direction. Along the first direction, one side of the elastic member is connected to the housing, and the other side is connected to the cell assembly. The housing includes a top wall and a bottom wall arranged along a second direction. The top wall is provided with a first extension, which includes a first extension connection portion connected to the front cover. The bottom wall is provided with a second extension, which includes a second extension connection portion connected to the front cover. Along the first direction, the length of the second extension connection portion is shorter than the length of the first extension connection portion. The first direction is perpendicular to the second direction. When the cell assembly expands, an expansion force acts on the elastic member, which in turn applies the expansion force to the housing. Over time, as the cell assembly continues to expand and the elastic member is compressed to its limit, the second extension connection portion is shorter than the first extension connection portion, making it easier for the elastic member to push open the bottom wall, thereby buffering the pressure of the cell assembly, reducing the risk of a pressure explosion in the cell assembly, and improving the safety of the battery pack.

[0198] The following describes some embodiments of the present application in detail with reference to the accompanying drawings. In the absence of conflict, the following embodiments and features of the embodiments may be combined with each other.

[0199] 1 and 2 , an embodiment of the present application provides a battery pack 100 , including a housing 10 a , a cell assembly 20 , and a front cover 10 b . The cell assembly 20 is disposed in the housing 10 a , and the front cover 10 b is connected to the housing 10 a .

[0200] In some embodiments, the battery pack 100 includes an elastic member 30 disposed within the housing 10 a , and the elastic member 30 and the battery cell assembly 20 are arranged along a first direction X. Along the first direction X, one side of the elastic member 30 is connected to the housing 10 a , and the other side of the elastic member 30 is connected to the battery cell assembly 20 .

[0201] In some embodiments, the elastic member 30 is disposed in the housing 10 a to facilitate disassembly and maintenance of the battery pack 100 .

[0202] In some embodiments, the elastic member 30 is configured to apply pressure to the battery cell assembly 20 and provide expansion space for the battery cell assembly 20 .

[0203] Referring to FIG. 3 to FIG. 14 , in some embodiments, the housing 10 a includes a top wall 11 , and the top wall 11 is connected to the front cover 10 b .

[0204] In some embodiments, the housing 10 a includes a bottom wall 12 , and the top wall 11 and the bottom wall 12 are arranged along a second direction Y, where the first direction X is perpendicular to the second direction Y.

[0205] In some embodiments, a first extension portion 111 is provided on the top wall 11, and the first extension portion 111 is connected to the front cover 10b. Optionally, the first extension portion 111 is connected to the inner surface of the front cover 10b.

[0206] In some embodiments, the first extension portion 111 is fixed to the front cover 10b.

[0207] In some embodiments, the first extension portion 111 and the top wall 11 are integrally formed, for example, integrally formed by an injection molding process, such as by bending or stamping a metal plate.

[0208] In some embodiments, the first extension portion 111 may be fixed to the top wall 11 by other means, including but not limited to welding, bonding, etc.

[0209] In some embodiments, a second extension portion 121 is provided on the bottom wall 12, and the second extension portion 121 is connected to the front cover 10b. Optionally, the second extension portion 121 is connected to the inner surface of the front cover 10b.

[0210] In some embodiments, the second extension portion 121 and the bottom wall 12 are integrally formed, for example, integrally formed by an injection molding process, such as by bending or stamping a metal plate.

[0211] In some embodiments, the second extension portion 121 may be fixed to the bottom wall 12 by other means, including but not limited to welding, bonding, etc.

[0212] In some embodiments, the second extension portion 121 is directly connected to the inner surface of the front cover 10 b , wherein direct connection means that the second extension portion 121 and the front cover 10 b are directly connected without being connected via other components.

[0213] In some embodiments, the first extension portion 111 is fastened to the front cover 10 b , and fastening methods include but are not limited to fastening with fasteners, welding, bonding, etc.

[0214] In some embodiments, the battery pack 100 includes a fastener 101. The first extension 111 has a first hole 1111, and the front cover 10b has a second hole 101b. The fastener 101 is disposed in the first hole 1111 and the second hole 101b, so that the first extension 111 is fastened to the front cover 10b. Optionally, the fastener 101 includes a screw.

[0215] Referring to Figures 11 and 14 , in some embodiments, the first extension portion 111 includes a first extension connection portion 112, which is connected to the front cover 10b. The second extension portion 121 includes a second extension connection portion 122, which is connected to the front cover 10b. Along the first direction X, the length D2 of the second extension connection portion 122 is less than the length D1 of the first extension connection portion 112. When the battery cell assembly 20 expands, the expansion force acts on the elastic member 30, which in turn applies the expansion force to the housing 10a. Over time, as the battery cell assembly 20 continues to expand and the elastic member 30 is compressed to its limit, the length D2 of the second extension connection portion 122 is less than the length D1 of the first extension connection portion 112. This facilitates the elastic member 30 to push open the bottom wall 12, buffering the pressure of the battery cell assembly 20, reducing the risk of pressure explosion within the battery cell assembly 20, and improving the safety of the battery pack 100. It is understandable that in other embodiments, there may be a situation where the elastic member 30 is not compressed to the limit and the battery cell assembly 20 breaks through the bottom wall 12 .

[0216] In some embodiments, the rigidity of the first extension portion 111 is greater than that of the second extension portion 121 , which facilitates the bottom wall 12 to be pushed open by the elastic member 30 and buffers the pressure of the battery cell assembly 20 .

[0217] In some embodiments, the first extending connection portion 112 has a greater rigidity than the second extending connection portion 122 , which facilitates the bottom wall 12 to be pushed open by the elastic member 30 before the top wall 11 , thereby buffering the pressure of the battery cell assembly 20 .

[0218] In some embodiments, the first extending connection portion 112 is configured as a regular structure, such as a rectangle, a square, etc.

[0219] In some embodiments, the second extending connection portion 122 is configured as a regular structure, such as a rectangle, a square, etc.

[0220] In some other embodiments, the first extending connection portion 112 is configured as an irregular structure, and the length D1 of the first extending connection portion 112 refers to the maximum length of the first extending connection portion 112 in the first direction X.

[0221] In some other embodiments, the second extending connection portion 122 is configured as an irregular structure, and the length D2 of the second extending connection portion 122 refers to the maximum length of the second extending connection portion 122 in the first direction X.

[0222] In some embodiments, the first extending portion 111 includes a first bending portion 113, and the first extending connecting portion 112 is connected to the first bending portion 113. The elastic member 30 abuts against the first bending portion 113, which helps to increase the connection strength between the elastic member 30 and the housing 10a.

[0223] In some embodiments, the second extension portion 121 includes a second bending portion 123 , the second extension connection portion 122 is connected to the second bending portion 123 , and the elastic member 30 abuts against the second bending portion 123 , which helps to increase the connection strength between the elastic member 30 and the housing 10 a .

[0224] In some embodiments, the rigidity of the top wall 11 is greater than the rigidity of the bottom wall 12 , which further facilitates the battery cell assembly 20 to rush out from the side where the bottom wall 12 is located, thereby further improving the safety of the battery pack 100 .

[0225] In some embodiments, the first extension portion 111 and the second extension portion 121 are located inside the front cover 10b, so that the front cover 10b has a limiting effect on the first extension portion 111 and the second extension portion 121, which is beneficial for the connection of the housing 10a to the front cover 10b.

[0226] In some embodiments, the top wall 11 defines a first fixing portion 11 a . Along the first direction X, a projection of the first fixing portion 11 a overlaps with a projection of the elastic member 30 . The elastic member 30 is fixed to the first fixing portion 11 a .

[0227] In some embodiments, fixing includes but is not limited to abutting, bonding, welding, fastener locking and fixing, snap connection, etc.

[0228] In some embodiments, the top wall 11 is provided with a plurality of first extension portions 111 , and the first fixing portion 11 a is provided between adjacent first extension portions 111 , which is beneficial for uniform stress and uniform deformation of the elastic member 30 .

[0229] In some embodiments, the bottom wall 12 defines a second fixing portion 12 a . Along the first direction X, a projection of the second fixing portion 12 a overlaps with a projection of the elastic member 30 . The elastic member 30 is fixed to the second fixing portion 12 a .

[0230] In some embodiments, the bottom wall 12 is provided with a plurality of second fixing portions 12 a , and the plurality of second fixing portions 12 a are provided between adjacent second extending portions 121 , which is beneficial for uniform stress and uniform deformation of the elastic member 30 .

[0231] In some embodiments, the first fixing portion 11 a and the second fixing portion 12 a are arranged along the second direction Y, which is beneficial for the elastic member 30 to be uniformly stressed and deformed.

[0232] In some embodiments, the housing 10 a includes a first side wall 13 connecting the top wall 11 and the bottom wall 12 .

[0233] In some embodiments, the first side wall 13 is provided with a first fixing member 131, and the first fixing member 131 is fixedly connected to the front cover 10b. Optionally, the fastener 101 passes through the front cover 10b and the first fixing member 131 to lock the first side wall 13 and the front cover 10b.

[0234] In some embodiments, along the second direction Y, one side of the first side wall 13 is fixedly connected to the top wall 11, and the other side is directly connected to the bottom wall 12, which facilitates the elastic member 30 to break open the bottom wall 12. Optionally, the first side wall 13 is locked and connected to the front cover 10b and the top wall 11 by a fastener 101.

[0235] In some embodiments, the housing 10a includes a second side wall 14 connecting the top wall 11 and the bottom wall 12. The first side wall 13 and the second side wall 14 are arranged along a third direction Z. The first direction X, the second direction Y, and the third direction Z are perpendicular to each other.

[0236] In some embodiments, the second side wall 14 is provided with a second fixing member 141, and the second fixing member 141 is fixedly connected to the front cover 10b. Optionally, the fastener 101 passes through the front cover 10b and the second fixing member 141 to lock the second side wall 14 and the front cover 10b.

[0237] In some embodiments, along the second direction Y, one side of the second side wall 14 is fixedly connected to the top wall 11, and the other side is directly connected to the bottom wall 12, which facilitates the elastic member 30 to break open the bottom wall 12. Optionally, the second side wall 14 is locked and connected to the front cover 10b and the top wall 11 by a fastener 101.

[0238] In some embodiments, the first side wall 13 is provided with a third fixing portion 13a, and the elastic member 30 is fixed to the third fixing portion 13a. Optionally, the elastic member 30 abuts against the third fixing portion 13a.

[0239] In some embodiments, the second sidewall 14 is provided with a fourth fixing portion 14a, and the third fixing portion 13a and the fourth fixing portion 14a are arranged along the third direction Z. The elastic member 30 is fixed to the fourth fixing portion 14a. Optionally, the elastic member 30 abuts against the fourth fixing portion 14a.

[0240] Through the first fixing portion 11a, the second fixing portion 12a, the third fixing portion 13a and the fourth fixing portion 14a, the elastic member 30 abuts against the housing 10a on both sides along the second direction Y and on both sides along the third direction Z, which is conducive to uniform force and uniform deformation of the elastic member 30.

[0241] In some embodiments, the housing 10a includes a rear wall 15 connecting the top wall 11 , the bottom wall 12 , the first side wall 13 , and the second side wall 14 . Along the first direction X, the battery cell assembly 20 is located between the elastic member 30 and the rear wall 15 .

[0242] In some embodiments, the elastic member 30 has a stiffness greater than that of the rear wall 15 . When the battery cell assembly 20 expands, the elastic member 30 deforms before the rear wall 15 . The elastic member 30 provides expansion space for the battery cell assembly 20 .

[0243] 15 to 19 , in some embodiments, the battery pack 100 includes a circuit board 40 disposed on the front cover 10 b and a first component 41 disposed on a side of the circuit board 40 facing the elastic member 30 .

[0244] In some embodiments, the first component 41 includes a fuse device.

[0245] In some embodiments, the fuse device may be a circuit breaker. As an example, the circuit breaker may be a fuse, or a short-circuit device having a fuse structure.

[0246] In some embodiments, the fuse device may be provided in the power circuit of the battery pack 100. It is understandable that, optionally, the power circuit of the battery pack 100 may include a discharge circuit for discharging the battery pack 100 to the outside, and may also include a charging circuit for charging the battery pack 100.

[0247] Referring to FIG. 19 , in some embodiments, along the second direction Y, the distance between the first component 41 and the top wall 11 is L1, and the distance between the first component 41 and the bottom wall 12 is L2, where L1 is smaller than L2. By placing the first component 41 closer to the top wall 11, the risk of damage to the first component 41 when the elastic member 30 breaks through the bottom wall 12 and the battery cell assembly 20 breaks out of the bottom wall 12 is reduced.

[0248] In some embodiments, when measuring L1 and L2 , the test position on the first component 41 is the highest point where the first component 41 protrudes from the circuit board 40 .

[0249] In some embodiments, along the second direction Y, the distance between the bottom wall 12 and the top wall 11 is L0, and L1 is less than 1 / 4 L0, further reducing the risk of the battery cell assembly 20 contacting the first component 41 and causing damage to the first component 41.

[0250] In some embodiments, along the first direction X, the first component 41 protrudes out of the circuit board 40 more than other components.

[0251] Optionally, the circuit board 40 includes a BMS assembly (Battery Management System), which includes multiple electronic components. The multiple electronic components can realize functions such as control, protection, communication, power calculation, signal transmission, and power transmission of the battery cell assembly 20.

[0252] Optionally, the circuit board 40 includes a flexible printed circuit (FPC). Optionally, the circuit board 40 includes a printed circuit board (PCB).

[0253] Referring to FIG. 20 to FIG. 28 , in some embodiments, the battery cell assembly 20 includes a plurality of battery cell units 20 a , and the plurality of battery cell units 20 a are stacked along a first direction X.

[0254] In some embodiments, the battery cell unit 20a includes a first battery cell unit 201 and a second battery cell unit 202 , wherein the first battery cell unit 201 and the second battery cell unit 202 are located at the outermost battery cell units of the battery cell assembly 20 , wherein the first battery cell unit 201 is connected to the elastic member 30 , and the second battery cell unit 202 is connected to the rear wall 15 .

[0255] In some embodiments, the battery cell unit 20a includes a battery cell 21, the battery cell 21 includes a battery cell shell 21a, an electrode assembly 21b and an electrode terminal 21c, the battery cell shell 21a includes a main body 211, the electrode assembly 21b is located in the main body 211, and the electrode terminal 21c is connected to the electrode assembly 21b and extends out of the battery cell shell 21a.

[0256] In some embodiments, the battery cell unit 20 a is connected to the bottom wall 12 , and the battery cell unit 20 a is configured such that when the battery cell 21 expands, the battery cell unit 20 a moves relative to the bottom wall 12 in a direction opposite to the first direction X.

[0257] In some embodiments, the battery cell unit 20 a is connected to the bottom wall 12 , and the battery cell unit 20 a is configured to move relative to the bottom wall 12 along the first direction X when the expansion of the battery cell 21 decreases.

[0258] In some embodiments, the battery pack 100 includes a first insulating sheet 110 . The first insulating sheet 110 is disposed between the bottom wall 12 and the battery cell assembly 20 to enhance insulation between the battery cell assembly 20 and the bottom wall 12 .

[0259] In some embodiments, the battery cell assembly 20 is connected to the first insulating sheet 110, for example, the battery cell assembly 20 is in contact with the first insulating sheet 110. The battery cell unit 20a is configured so that when the battery cell unit 20a expands, the battery cell unit 20a moves on the first insulating sheet 110 in a direction opposite to the first direction X.

[0260] In some embodiments, the battery cell assembly 20 is connected to the first insulating sheet 110, for example, the battery cell assembly 20 is in contact with the first insulating sheet 110. The battery cell unit 20a is configured to move on the first insulating sheet 110 along the first direction X when the expansion of the battery cell 21 decreases.

[0261] In some embodiments, the friction coefficient between the battery cell unit 20 a and the first insulating sheet 110 is smaller than the friction coefficient between the battery cell unit 20 a and the bottom wall 12 , which facilitates the movement of the battery cell unit 20 a .

[0262] In some embodiments, the cell casing 21 a includes a sealing portion 212 , the sealing portion 212 is connected to the main body 211 , and the electrode terminal 21 c extends from the sealing portion 212 out of the cell casing 21 a .

[0263] In some embodiments, the main body 211 includes a first shell 2111 and a second shell 2112. The first shell 2111 is provided with a first recess 2111a, and the second shell 2112 is provided with a second recess 2112a. The first shell 2111 is connected to the second shell 2112 to form a storage space. The electrode assembly 21b is partially provided in the first recess 2111a, and partially provided in the second recess 2112a. The circumference of the first shell 2111 extends outward to form a first extended edge 2113, and the circumference of the second shell 2112 extends outward to form a second extended edge 2114. After the first shell 2111 is connected to the second shell 2112, the first extended edge 2113 and the second extended edge 2114 overlap and are sealed together to form a sealing portion 212.

[0264] In some embodiments, the sealing portion 212 includes a first sealing portion 212 a , and the electrode terminal 21 c extends from the first sealing portion 212 a out of the cell housing 21 a .

[0265] In some embodiments, the sealing portion 212 includes a second sealing portion 212 b connected to the first sealing portion 212 a .

[0266] In some embodiments, the first extended edge 2113 and the second extended edge 2114 overlap and are sealed to form two first sealing portions 212a and two second sealing portions 212b. The two first sealing portions 212a are arranged along the third direction Z, and the two second sealing portions 212b are arranged along the second direction Y. One first sealing portion 212a connects the two second sealing portions 212b, and the other first sealing portion 212a connects the two second sealing portions 212b.

[0267] In some embodiments, the battery cell 21 includes two electrode terminals 21c, wherein one electrode terminal 21c extends from one of the two first sealing portions 212a out of the battery cell housing 21a, and the other electrode terminal 21c extends from the other of the two first sealing portions 212a out of the battery cell housing 21a.

[0268] In some embodiments, two electrode terminals 21 c extend out of the cell casing 21 a from the same first sealing portion 212 a .

[0269] In one embodiment, adjacent main body portions 211 are in contact and connected, which facilitates pressurization of the main body portions 211 .

[0270] In one embodiment, adjacent battery cell casings 21 a exert pressure on each other, so that the plurality of battery cell units 20 a are in a pressurized state, which is beneficial for improving the service life of the battery cell units 20 a.

[0271] In some embodiments, the first sealing portion 212a includes a first sealing connection portion 2121 and two first sealing bend portions 2122. The first sealing connection portion 2121 connects the two first sealing bend portions 2122. The two first sealing bend portions 2122 are arranged opposite each other along the second direction Y. The electrode terminal 21c extends from the first sealing connection portion 2121 out of the battery cell housing 21a.

[0272] In some embodiments, the cell housing 21 a includes an aluminum-plastic film.

[0273] In some embodiments, the battery cell 21 includes but is not limited to a soft-pack battery cell, a square battery cell, and a round battery cell.

[0274] In some embodiments, each battery cell unit 20 a further includes a bracket 22 , which covers at least a portion of the battery cell casing 21 a .

[0275] In some embodiments, the bracket 22 is configured such that, when the battery cell 21 expands, the bracket 22 moves relative to the housing 10 a in a direction opposite to the first direction X.

[0276] In some embodiments, the bracket 22 is configured to move relative to the housing 10 a along the first direction X when the expansion of the battery cell 21 decreases.

[0277] In some embodiments, the bracket 22 is connected to the bottom wall 12 , and the bracket 22 is configured to move relative to the bottom wall 12 in a direction opposite to the first direction X when the battery cell 21 expands.

[0278] In some embodiments, the bracket 22 is connected to the bottom wall 12 , and the bracket 22 is configured to move relative to the bottom wall 12 along the first direction X when the expansion of the battery cell 21 decreases.

[0279] In some embodiments, the bracket 22 is in contact with and connected to the first insulating sheet 110 . The bracket 22 is configured to move on the first insulating sheet 110 in a direction opposite to the first direction X when the battery cell 21 expands.

[0280] In some embodiments, the bracket 22 contacts and connects to the first insulating sheet 110 , and the bracket 22 is configured to move on the first insulating sheet 110 along the first direction X when the expansion of the battery cell 21 decreases.

[0281] In some embodiments, the bracket 22 is integrally formed with the battery cell 21, which can enhance the connection strength between the bracket 22 and the battery cell 21. Integral formation refers to direct fixation of the bracket 22 and the battery cell 21. Integral formation methods include, but are not limited to, potting and injection molding.

[0282] In some embodiments, after the insulating material is placed around the battery cell 21 through a pouring process, the insulating material is solidified to form a bracket 22, and the bracket 22 and the battery cell 21 are bonded and fixed. For example, the battery cell 21 is placed in a mold, and the insulating material is poured into the mold. After the insulating material is solidified to form the bracket 22 and is bonded and fixed to the battery cell 21, the bracket 22 and the battery cell 21 are taken out of the mold.

[0283] In some embodiments, the insulating material includes but is not limited to potting compound and foaming compound.

[0284] In some embodiments, the injection molding process includes placing the battery cell 21 into a mold, heating and melting the insulating material with an injection molding machine, allowing the melted insulating material to flow into the mold, and solidifying the insulating material to form the bracket 22, which is bonded and fixed to the battery cell 21. The bracket 22 and battery cell 21 are then removed from the mold. Optionally, the insulating material includes polyamide.

[0285] In some embodiments, the bracket 22 is an insulating bracket, which can reduce the risk of short circuit between the bracket 22 and the battery cell 21 .

[0286] In some embodiments, the bracket 22 includes a first bracket 22 a that covers at least a portion of the sealing portion 212 .

[0287] In some embodiments, the first bracket 22a includes at least one first side portion 222, and each first side portion 222 covers a first sealing bend portion 2122. By the first bracket 22a covering the first sealing portion 212a, protection of the first sealing portion 212a is increased.

[0288] In some embodiments, the first side portion 222 is connected to the bottom wall 12 . The first side portion 222 is configured such that when the battery cell 21 expands, the first side portion 222 moves relative to the bottom wall 12 in a direction opposite to the first direction X.

[0289] In some embodiments, the first side portion 222 is connected to the bottom wall 12 . The first side portion 222 is configured to move relative to the bottom wall 12 along the first direction X when the expansion of the battery cell 21 decreases.

[0290] In some embodiments, the first side portion 222 is connected to the first insulating sheet 110 . The first side portion 222 is configured such that, when the battery cell 21 expands, the first side portion 222 moves on the first insulating sheet 110 in a direction opposite to the first direction X. For example, the first side portion 222 contacts and connects to the first insulating sheet 110 .

[0291] In some embodiments, the first side portion 222 is connected to the first insulating sheet 110 and is configured such that, when the battery cell 21 expands less, the first side portion 222 moves on the first insulating sheet 110 along the first direction X. For example, the first side portion 222 contacts and connects to the first insulating sheet 110 .

[0292] In some embodiments, the first bracket 22 a includes two first side portions 222 , and the first side portions 222 are arranged along the second direction Y. One of the first side portions 222 is connected to the first insulating sheet 110 .

[0293] When the battery cell 21 expands, the first sealing portion 212a can move relative to the first insulating sheet 110 through the first side portion 222, and the first side portion 222 can reduce the friction between the first sealing portion 212a and the first insulating sheet 110 during movement, thereby facilitating movement and protecting the first sealing portion 212a, and reducing the risk of damage to the first sealing portion 212a and affecting the use of the battery pack 100.

[0294] In some embodiments, the first bracket 22a includes a first connecting portion 221 , and the first connecting portion 221 covers at least a portion of the first sealing connecting portion 2121 to increase protection for the first sealing portion 212a.

[0295] In some embodiments, along the second direction Y, one end of the first connecting portion 221 is connected to the first side portion 222 , and the other end is connected to another first side portion 222 , which can increase the structural strength of the first bracket 22a and is beneficial to protecting the first sealing portion 212a .

[0296] In some embodiments, the first bracket 22a includes at least one first side extension 224, which covers a portion of the main body 211. The first side extension 224 can protect the main body 211 and increase the connection strength between the first bracket 22a and the battery cell 21.

[0297] In some embodiments, the first bracket 22a includes at least one first side extension 224. The first side extension 224 covers a portion of the main body 211 and one of the second sealing portions 212b. The first side extension 224 and the second sealing portion 212b are located on the same side of the main body 211. The first side extension 224 protects the main body 211 and the second sealing portion 212b and increases the connection strength between the first bracket 22a and the battery cell 21.

[0298] In some embodiments, the first bracket 22a includes two first side extensions 224, which are arranged along the second direction Y. One of the first side extensions 224 covers a portion of the main body 211 and one of the second sealing portions 212b, and the first side extension 224 and the second sealing portion 212b are located on the same side of the main body 211. The other first side extension 224 covers a portion of the main body 211 and the other second sealing portion 212b, and the first side extension 224 and the second sealing portion 212b are located on the same side of the main body 211. The first side extensions 224 protect the main body 211 and the second sealing portion 212b and increase the connection strength between the first bracket 22a and the battery cell 21.

[0299] In some embodiments, the first side extension 224 is connected to the bottom wall 12 . The first side extension 224 is configured to move relative to the bottom wall 12 in a direction opposite to the first direction X when the battery cell 21 expands.

[0300] In some embodiments, the first side extension 224 is connected to the bottom wall 12 . The first side extension 224 is configured to move relative to the bottom wall 12 along the first direction X when the expansion of the battery cell 21 decreases.

[0301] In some embodiments, the first side extension 224 is connected to the first insulating sheet 110 . The first side extension 224 is configured such that, when the battery cell 21 expands, the first side extension 224 moves on the first insulating sheet 110 in a direction opposite to the first direction X. For example, the first side extension 224 contacts and connects to the first insulating sheet 110 .

[0302] In some embodiments, the first side extension 224 is connected to the first insulating sheet 110 . The first side extension 224 is configured such that, when the battery cell 21 expands less, the first side extension 224 moves on the first insulating sheet 110 along the first direction X. For example, the first side extension 224 contacts and connects to the first insulating sheet 110 .

[0303] When the battery cell 21 expands, the main body 211 can move on the first insulating sheet 110 through the first side extension portion 224, and the first side extension portion 224 can reduce the friction between the main body 211 and the first insulating sheet 110 during movement, thereby facilitating movement and protecting the main body 211, and reducing the risk of damage to the main body 211 and affecting the use of the battery pack 100.

[0304] In some embodiments, the first side extension portion 224 extends from the first side portion 222 , which helps to strengthen the connection strength between the first side extension portion 224 and the first side portion 222 .

[0305] In some embodiments, the main body 211 includes a first wall 211 c , and the first sealing portion 212 a is connected to the first wall 211 c .

[0306] In some embodiments, the first bracket 22a includes a second connecting portion 226, which covers a portion of the first wall 211c to protect the main body 211. One end of the first connecting portion 221 is connected to one of the first side portions 222, and the other end is connected to the other first side portion 222. One end of the second connecting portion 226 is connected to one of the first side portions 222, and the other end is connected to the other first side portion 222. This can further increase the structural strength of the first bracket 22a and further facilitate the protection of the first sealing portion 212a.

[0307] In some embodiments, the first bracket 22a includes two second connecting portions 226 and two first walls 211c.

[0308] In some embodiments, the first bracket 22 a includes a protrusion 227 , which protrudes from the first connection portion 221 in a direction opposite to the second direction Y.

[0309] In some embodiments, the battery pack 100 includes a detection member (not shown). A receiving groove 227a is provided on the side of the protrusion 227 facing away from the electrode terminal 21c. The detection member is received within the receiving groove 227a. The detection member is configured to detect the temperature of the battery cell 21. Optionally, the detection member is configured to detect the temperature of the electrode terminal 21c, which helps improve the accuracy of detecting the temperature of the battery cell 21.

[0310] 24 , viewed from a direction opposite to the first direction X, the electrode terminal 21 c is not blocked by the protrusion 227 . In some embodiments, the main body 211 includes two second walls 211 d , which are arranged in the first direction X. The first wall 211 c connects the second wall 211 d and the first sealing portion 212 a .

[0311] In some embodiments, please refer to Figure 28, observing along the third direction Z, in the first direction X, the second connecting portion 226 does not exceed the second wall 211d, the main bodies 211 of adjacent battery cells 21 can be in contact and connected, and the adjacent battery cells 21 apply pressure to each other through the main bodies 211.

[0312] In some embodiments, please refer to Figure 28, observing along the third direction Z, in the first direction X, the second connecting portion 226 is located between the two second walls 211d. When the main bodies 211 of adjacent battery cells 21 apply pressure to each other, the force on the first sealing portion 212a can be reduced, thereby improving the protection of the first sealing portion 212a.

[0313] In some embodiments, please refer to Figure 28, observing along the third direction Z, in the first direction X, the first side portion 222 is located between the two second walls 211d. When the main bodies 211 of adjacent battery cells 21 apply pressure to each other, the force on the first sealing portion 212a can be reduced, thereby improving the protection of the first sealing portion 212a.

[0314] In some embodiments, when viewed along the third direction Z, in the first direction X, the first side extension portion 224 is located between the two second walls 211d. When the main bodies 211 of adjacent battery cells 21 apply pressure to each other, the force on the first sealing portion 212a can be reduced, thereby improving the protection of the first sealing portion 212a.

[0315] In some embodiments, the bracket 22 includes a second bracket 22 b connected to another first sealing portion 212 a .

[0316] In some embodiments, the first bracket 22a and the second bracket 22b have the same structure.

[0317] In some embodiments, the first bracket 22a and the second bracket 22b are similar, so repeated description of the same or similar configurations as the first bracket of the previous embodiment will be omitted, and hereinafter, focus will be placed on structures different from the previous embodiment.

[0318] Please refer to Figures 24 and 25. In some embodiments, the second bracket 22b is provided with a notch 228, and a portion of the first sealing connection portion 2121 of another first sealing portion 212a is located in the notch 228. When the battery cell 21 expands, the pressure inside the battery cell 21 can be discharged through the first sealing connection portion 2121 in the notch 228, which is conducive to pressure relief and improves the safety of the battery cell unit 20a.

[0319] In some embodiments, the notch 228 and the detection member are provided on different brackets to reduce the risk of damaging the detection member during pressure relief.

[0320] In some embodiments, the first bracket 22a may be provided with a notch 228 as shown in the second bracket 22b.

[0321] Referring to FIG. 25 , in some embodiments, the second bracket 22 b is not provided with the protrusion 227 shown in FIG. 23 .

[0322] Referring to Figures 10 to 13 , in some embodiments, the top wall 11 is provided with two first stoppers 11b , spaced apart along the third direction Z, each extending along the first direction X. The main body 211 is disposed between the two first stoppers 11b , further guiding the movement of the battery cell assembly 20 through the two first stoppers 11b . Optionally, the two first stoppers 11b guide the movement of the battery cell assembly 20 in a direction opposite to the first direction X. Optionally, the first stoppers 11b are formed by protruding from the top wall 11 toward the bottom wall 12 .

[0323] In some embodiments, the main body 211 of each battery cell unit 20 a is disposed between two first limiting portions 11 b .

[0324] Referring to Figures 2 and 12 , in some embodiments, the bottom wall 12 is provided with two second limiting portions 12b, spaced apart along the third direction Z, and each second limiting portion 12b extending along the first direction X. The main body 211 is disposed between the two second limiting portions 12b, and the two second limiting portions 12b guide the movement of the battery cell assembly 20. Optionally, the two second limiting portions 12b guide the movement of the battery cell assembly 20 in a direction opposite to the first direction X. Optionally, the second limiting portions 12b are formed by protruding from the bottom wall 12 toward the top wall 11.

[0325] In some embodiments, the main body 211 of each battery cell unit 20a is disposed between two second limiting portions 12b.

[0326] In some embodiments, the bottom wall 12 is provided with two second limiting portions 12 b , and the top wall 11 is provided with two first limiting portions 11 b .

[0327] Referring to Figures 2, 4, 7 and 8, in some embodiments, the elastic member 30 includes a base 31, a buffer portion 32 and a connecting portion 33. The base 31 is connected to the battery cell assembly 20, and the buffer portion 32 connects the base 31 and the connecting portion 33.

[0328] In some embodiments, the connecting portion 33 is fixed to the housing 10 a .

[0329] In some embodiments, along the first direction X, the battery cell assembly 20 is located between the base 31 and the rear wall 15 , the rear wall 15 is connected to the battery cell assembly 20 , the base 31 is connected to the battery cell assembly 20 , and the base 31 is configured to apply pressure to the battery cell assembly 20 .

[0330] In some embodiments, the base 31 is connected to the first battery cell unit 201. Alternatively, the base 31 is in contact with and connected to the first battery cell unit 201. Alternatively, the base 31 and the first battery cell unit 201 may provide other component connections.

[0331] In some embodiments, the battery pack 100 includes a first buffer member 120, which is disposed between the base 31 and the first battery cell unit 201. Optionally, the first buffer member 120 includes foam.

[0332] In some embodiments, the hardness of the first buffer 120 is less than that of the base 31 , thereby reducing damage to the first battery cell 201 caused by the base 31 .

[0333] In some embodiments, the rear wall 15 is connected to the second battery cell unit 202 .

[0334] In some embodiments, the battery pack 100 includes a second buffer member 130, which is disposed between the second battery cell unit 202 and the rear wall 15. Optionally, the second buffer member 130 includes foam.

[0335] In some embodiments, the hardness of the second buffer 130 is less than that of the rear wall 15 , thereby reducing damage to the second battery cell unit 202 caused by the rear wall 15 .

[0336] In some embodiments, along the first direction X, the projection of the main body 211 is located within the projection of the base 31 , which increases the interaction area between the base 31 and the main body 211 and facilitates the base 31 to apply pressure to the main body 211 .

[0337] In some embodiments, the foam material includes ethylene vinyl acetate (EVA).

[0338] 3 , 15 , and 20 , in some embodiments, the battery pack 100 includes a first conductive member 50 . Along the second direction Y, a first gap 301 is defined between the base 31 and the housing 10a . One end of the first conductive member 50 is connected to the battery cell assembly 20 , and the other end passes through the first gap 301 .

[0339] In some embodiments, along the second direction Y, a first gap 301 is defined between the base 31 and the second sidewall 14 .

[0340] In some embodiments, one end of the first conductive member 50 is connected to the first battery cell unit 201 .

[0341] In some embodiments, the first conductive member 50 is fixed to the elastic member 30 .

[0342] In some embodiments, the first conductive member 50 is configured to move with the elastic member 30. When the battery cell expands, vibrates, or falls, the first conductive member 50 moves with the elastic member 30, thereby reducing the pulling on the first conductive member 50 and the risk of the first conductive member 50 being broken, thereby improving the safety of the battery pack 100. Optionally, the first conductive member 50 includes a wiring harness.

[0343] In some embodiments, the first conductive member 50 is configured to transmit power to the battery cell assembly 20. The first conductive member 50 can transmit power to the battery cell assembly 20. When the battery pack 100 is discharging, the electrical energy of the battery cell assembly 20 can be transmitted to the load of the electrical device through the first conductive member 50, thereby powering the load of the electrical device. When the battery pack 100 is charging, external electrical energy can be transmitted to the battery cell assembly 20 through the first conductive member 50, thereby charging the battery cell assembly 20.

[0344] In some embodiments, the battery pack 100 includes a second conductive member 60 , with a second gap 302 defined between the base 31 and the housing 10 a . One end of the second conductive member 60 is connected to the battery cell assembly 20 , and the other end passes through the second gap 302 .

[0345] In some embodiments, a second gap 302 is defined between the base 31 and the first sidewall 13 .

[0346] In some embodiments, one end of the second conductive member 60 is connected to the second battery cell unit 202 .

[0347] In some embodiments, the second conductive member 60 and the elastic member 30 are disposed separately. When the battery cell expands, vibrates, or falls, the second conductive member 60 and the elastic member 30 are disposed separately, which helps reduce pulling on the second conductive member 60, reduces the risk of the second conductive member 60 being broken, and improves the safety of the battery pack 100. Optionally, the second conductive member 60 includes a wiring harness.

[0348] In some embodiments, the second conductive member 60 is configured to transmit power to the battery cell assembly 20. The second conductive member 60 can transmit power to the battery cell assembly 20. When the battery pack is discharging, the electrical energy of the battery cell assembly 20 can be transmitted to the load of the electrical device through the second conductive member 60 to power the load of the electrical device. When the battery pack is charging, external electrical energy can be transmitted to the battery cell assembly 20 through the second conductive member 60 to charge the battery cell assembly 20.

[0349] In some embodiments, one of the first conductive member 50 and the second conductive member 60 is connected to the common positive terminal of the battery cell assembly 20 , and the other is connected to the common negative terminal of the battery cell assembly 20 .

[0350] In some embodiments, the buffer portion 32 is configured to provide expansion space for the battery cell assembly 20 .

[0351] In some embodiments, the buffer portion 32 includes a first buffer portion 321 connected to the base portion 31 . The first buffer portion 321 can act on the battery cell assembly 20 through the base portion 31 . The first buffer portion 321 is configured to provide expansion space for the battery cell assembly 20 .

[0352] In some embodiments, the buffer portion 32 includes a second buffer portion 322 . The first buffer portion 321 and the second buffer portion 322 are disposed opposite each other along the second direction Y. The first buffer portion 321 is connected to one side of the base portion 31 , and the second buffer portion 322 is connected to the other side of the base portion 31 . The second buffer portion 322 can act on the battery cell assembly 20 through the base portion 31 , and is configured to provide expansion space for the battery cell assembly 20 .

[0353] In some embodiments, the connecting portion 33 includes a first connecting portion 331 connected to the first buffer portion 321 .

[0354] In some embodiments, along the first direction X, the projection of the first connecting portion 331 overlaps with the projection of the first fixing portion 11 a . The first connecting portion 331 is fixed to the first fixing portion 11 a to transfer the force acting on the buffer portion 32 to the housing 10 a .

[0355] In some embodiments, the first connecting portion 331 is fixed to the third fixing portion 13a, which is beneficial for transferring the force exerted on the buffer portion 32 to the housing 10a. Optionally, the first connecting portion 331 abuts against the third fixing portion 13a.

[0356] In some embodiments, the first connecting portion 331 is fixed to the fourth fixing portion 14a, which is beneficial for transferring the force exerted on the buffer portion 32 to the housing 10a. Optionally, the first connecting portion 331 abuts against the fourth fixing portion 14a.

[0357] In some embodiments, the connecting portion 33 includes a second connecting portion 332 , and the first connecting portion 331 and the second connecting portion 332 are disposed opposite to each other along the second direction Y. The second connecting portion 332 is connected to the second buffer portion 322 .

[0358] In some embodiments, along the first direction X, the projection of the second fixing portion 12 a overlaps with the projection of the second connecting portion 332 . The second connecting portion 332 is fixed to the second fixing portion 12 a to transfer the force acting on the buffer portion 32 to the housing 10 a .

[0359] In some embodiments, the second connecting portion 332 is fixed to the third fixing portion 13a, which is beneficial for transferring the force acting on the buffer portion 32 to the housing 10a. Optionally, the second connecting portion 332 abuts against the third fixing portion 13a.

[0360] In some embodiments, the second connecting portion 332 is fixed to the fourth fixing portion 14a, which is beneficial for transferring the force acting on the buffer portion 32 to the housing 10a. Optionally, the second connecting portion 332 abuts against the fourth fixing portion 14a.

[0361] The present application is fixed to the first fixing part 11a, the third fixing part 13a and the fourth fixing part 14a through the first connecting part 331, and the second connecting part 332 connects the second fixing part 12a, the third fixing part 13a and the fourth fixing part 14a, which is conducive to uniform force and uniform deformation of the elastic part 30.

[0362] In some embodiments, the strength of the top wall 11 , the bottom wall 12 , the first side wall 13 and the second side wall 14 is greater than the strength of the elastic member 30 , thereby reducing the risk of deformation of the top wall 11 , the bottom wall 12 , the first side wall 13 and the second side wall 14 due to the force exerted on the buffer portion 32 .

[0363] Referring to FIG. 5 to FIG. 8 , in some embodiments, the first buffer portion 321 includes a first section 321 a and a second section 321 b . The first section 321 a is connected to the base 31 , and the second section 321 b is connected to the first section 321 a and the first connecting portion 331 .

[0364] In some embodiments, the angle formed between the first section 321 a and the base 31 is the same as the angle formed between the second section 321 b and the first connecting portion 331 , which is beneficial for uniform stress and uniform deformation of the elastic member 30 .

[0365] In some embodiments, the second buffer portion 322 includes a third section 322 a and a fourth section 322 b . The third section 322 a is connected to the base portion 31 , and the fourth section 322 b is connected to the third section 322 a and the second connection portion 332 .

[0366] In some embodiments, the angle formed by the third section 322a and the base 31 is the same as the angle formed by the fourth section 322b and the second connecting portion 332, which is conducive to uniform stress and uniform deformation of the elastic member 30.

[0367] In some embodiments, the connecting portion 33 is provided with a flange 333, which is formed by folding over a side of the connecting portion 33 away from the buffer portion 32 in the second direction Y. Along the first direction X, the flange is located between the connecting portion 33 and the base 31. The flange 333 can reduce the risk of the connecting portion 33 cutting the wiring harness.

[0368] In some embodiments, along the first direction X, the projection of the flange 333 does not overlap with the projection of the buffer portion 32 , thereby reducing the impact on the deformation area of ​​the buffer portion 32 .

[0369] In some embodiments, the elastic member 30 includes a third bent portion 34. The third bent portion 34 abuts against the first bent portion 113, which helps to increase the connection strength between the elastic member 30 and the housing 10a.

[0370] In some embodiments, the elastic member 30 includes a fourth bent portion 35. The fourth bent portion 35 abuts against the second bent portion 123, which helps to increase the connection strength between the elastic member 30 and the housing 10a and helps the elastic member 30 to break through the bottom wall 12.

[0371] In some embodiments, the battery pack 100 includes a first connection terminal 102 and a second connection terminal 103, which are connected to the front cover 10b. One of the first connection terminal 102 and the second connection terminal 103 is connected to the circuit board 40, and the other is connected to the first conductive member 50. The first connection terminal 102 and the second connection terminal 103 protrude from the side of the front cover 10b facing away from the battery cell assembly 20 for connection to external devices.

[0372] Referring to Figure 3, in some embodiments, the battery pack 100 includes a sampling member 70 connected to each battery cell 21. The sampling member 70 is connected to the circuit board 40 to transmit the collected electrical signals from the battery cells 21 to the circuit board 40. Optionally, the electrode terminals 21c of adjacent battery cells 21 are stacked, and the sampling member 70 is connected to at least one of the stacked electrode terminals 21c. Optionally, the electrical signal includes information such as current, voltage, resistance, and temperature. The sampling member 70 is welded to the electrode terminals 21c, including but not limited to laser welding and ultrasonic welding.

[0373] In some embodiments, the battery pack 100 includes a wire 104 , and the detection component is connected to the sampling component 70 via the wire 104 .

[0374] 29 , the present application also provides an electrical device 200 that utilizes at least one of the aforementioned battery packs 100. In one embodiment, the electrical device 200 of the present application may be, but is not limited to, electronic equipment, drones, backup power supplies, electric vehicles, electric motorcycles, electric power-assisted bicycles, power tools, large household battery packs, and the like.

[0375] Those skilled in the art should recognize that the above embodiments are merely intended to illustrate the present application and are not intended to limit the present application. As long as they are within the spirit of the present application, appropriate changes and modifications to the above embodiments fall within the scope disclosed in the present application.

Claims

1. A battery pack, characterized in that, comprising: a battery cell assembly; a housing, wherein the battery cell assembly is disposed within the housing; a front cover, which is connected to the housing; an elastic member, the elastic member and the battery cell assembly are arranged along a first direction, and along the first direction, one side of the elastic member is connected to the housing and the other side is connected to the battery cell assembly; the housing includes a top wall and a bottom wall arranged along a second direction, the top wall is provided with a first extension portion, the first extension portion includes a first extension connection portion connected to the front cover, the bottom wall is provided with a second extension portion, the second extension portion includes a second extension connection portion connected to the front cover, and along the first direction, the length of the second extension connection portion is less than the length of the first extension connection portion; the first direction is perpendicular to the second direction.

2. The battery pack according to claim 1, characterized in that, the first extension portion is tightly connected to the front cover.

3. The battery pack according to claim 1 or 2, characterized in that, further comprising a circuit board, the circuit board is disposed on the front cover; a first component is provided on a side of the circuit board facing the elastic member; along the second direction, the distance from the first component to the top wall is L1, and the distance from the first component to the bottom wall is L2, and L1 is less than L2.

4. The battery pack according to claim 3, characterized in that, along the second direction, the distance between the bottom wall and the top wall is L0, and L1 is less than 1 / 4L0.

5. The battery pack according to claim 3 or 4, characterized in that, along the first direction, the first component protrudes from the circuit board more than other components.

6. The battery pack according to any one of claims 1 to 5, characterized in that, the first extension portion includes a first bending portion, the first bending portion connects the first extension connection portion, and the elastic member abuts against the first bending portion.

7. The battery pack according to claim 6, characterized in that, the second extension portion includes a second bending portion, the second bending portion connects the second extension connection portion, and the elastic member abuts against the second bending portion.

8. The battery pack according to claim 6 or 7, characterized in that, the elastic member includes a base portion, a buffer portion and a connecting portion, the base portion is connected to the battery cell assembly, and the buffer portion connects the connecting portion and the base portion; the connecting portion is fixed to the housing.

9. The battery pack according to claim 8, characterized in that, the buffer portion includes a first buffer portion, and the first buffer portion connects one side of the base portion; or, the buffer portion includes a first buffer portion and a second buffer portion, along the second direction, the first buffer portion and the second buffer portion are oppositely arranged, the first buffer portion connects one side of the base portion, and the second buffer portion connects the other side of the base portion.

10. The battery pack according to claim 9, characterized in that, the connecting portion includes a first connecting portion, and the elastic member includes a third bending portion, and the third bending portion abuts against the first bending portion.

11. The battery pack according to claim 10, characterized in that, The connecting portion includes a second connecting portion, and the first connecting portion and the second connecting portion are oppositely arranged along the second direction. The elastic member includes a fourth bending portion, and the fourth bending portion abuts against the second bending portion.

12. The battery pack according to claim 10 or 11, wherein, the top wall is provided with a first fixing portion, and the first connecting portion is fixed to the first fixing portion; along the first direction, the projection of the first fixing portion and the projection of the first connecting portion overlap; and / or, the bottom wall is provided with a second fixing portion, and the second connecting portion is fixed to the second fixing portion; along the first direction, the projection of the second fixing portion and the projection of the second connecting portion overlap.

13. The battery pack according to claim 12, wherein, the housing includes a first side wall and a second side wall, the first side wall and the second side wall are arranged along a third direction, the first side wall is fixedly connected to the front cover, the second side wall is fixedly connected to the front cover, and the first direction, the second direction and the third direction are perpendicular to each other in pairs; the first side wall is provided with a third fixing portion, and the first connecting portion and the second connecting portion are fixed to the third fixing portion; and / or, the second side wall is provided with a fourth fixing portion, and the first connecting portion and the second connecting portion are fixed to the fourth fixing portion.

14. The battery pack according to any one of claims 1 to 13, wherein, the first extension portion and the second extension portion are located within the front cover.

15. The battery pack according to any one of claims 1 to 14, wherein, the housing includes a rear wall, the rear wall connects the top wall and the bottom wall, along the first direction, the battery cell assembly is located between the elastic member and the rear wall, and the stiffness of the elastic member is less than the stiffness of the rear wall.

16. The battery pack according to claim 15, wherein, the battery cell assembly includes battery cell units, each battery cell unit includes a battery cell, the battery cell includes a battery cell housing, an electrode assembly and electrode terminals, the battery cell housing includes a main body portion, the electrode assembly is disposed in the main body portion, and the electrode terminals are connected to the electrode assembly and extend out of the battery cell housing; the top wall is provided with two first limiting portions, and the two first limiting portions are arranged along the third direction; the main body portion of each battery cell unit is disposed between the two first limiting portions; and / or, the bottom wall is provided with two second limiting portions, and the two second limiting portions are arranged along the third direction; the main body portion of each battery cell unit is disposed between the two second limiting portions; the first direction, the second direction and the third direction are perpendicular to each other in pairs.

17. The battery pack according to any one of claims 3 to 5, wherein, the first component includes a fusing device.

18. The battery pack according to any one of claims 1 to 17, wherein, the second extension portion is directly connected to the inner surface of the front cover.

19. A battery pack, wherein, comprising: a battery cell assembly; a housing, the battery cell assembly is disposed within the housing; a front cover, the front cover is connected to the housing; An elastic member, the elastic member and the battery cell assembly are arranged along a first direction, and along the first direction, one side of the elastic member is connected to the housing, and the other side is connected to the battery cell assembly; The housing includes a top wall and a bottom wall arranged along a second direction, the top wall is provided with a first extension portion, the first extension portion includes a first extension connection portion connected to the front cover, the bottom wall is provided with a second extension portion, and the second extension portion includes a second extension connection portion connected to the front cover; The stiffness of the first extension portion is greater than the stiffness of the second extension portion.

20. An electrical device, characterized in that, comprising at least one battery pack according to any one of claims 1 to 19.

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