Battery and electric apparatus

Abstract

A battery (100) and an electric apparatus. The battery (100) comprises a case (10), an electrode assembly (20) and a buffer member (30), wherein the case (10) comprises a first case (11) and a second case (12), the first case (11) comprises a bottom wall (111) and a side wall (112), the side wall (112) is located between the bottom wall (111) and the second case (12), and the second case (12) is connected to the side wall (112); the electrode assembly (20) is accommodated in the case (10); and the buffer member (30) is arranged between the side wall (112) and the electrode assembly (20), the buffer member (30) comprises an expansion layer (310), the surface of the expansion layer (310) comprises a recess (30a), and the recess (30a) is recessed towards at least one of the side wall (112) or the electrode assembly (20). By means of the provision of the buffer member (30) between the side wall (112) and the electrode assembly (20), the movement of the electrode assembly (20) when the battery (100) drops can be suppressed; moreover, by means of the recess (30a) formed on the surface of the expansion layer (310), the impact kinetic energy of the electrode assembly (20) when the electrode assembly (20) drops can be buffered and absorbed, thereby reducing the impact of the electrode assembly (20) on the side wall (112), and thus reducing the risk of weld seam bursting, and improving the drop safety of the battery (100).

Description

Battery and power consuming device TECHNICAL FIELD

[0001] The present application relates to the technical field of batteries, and in particular to a battery and a power consuming device. BACKGROUND

[0002] At present, lithium ion batteries are widely used in electronic devices such as mobile phones, notebook computers, power banks and the like, but there is a problem that they may catch fire or explode due to accidental falling during use. With the increasing energy density of lithium ion batteries, this problem is more prominent. Hard-shell batteries (such as steel shell batteries) are more and more widely used due to their higher safety compared with soft-pack batteries. However, since hard-shell batteries are usually sealed by welding, the electrode assembly inside the battery is prone to impact the weld during falling, which may cause the weld to be broken and bring safety risks.

[0003] SUMMARY

[0004] Therefore, it is necessary to provide a battery and a power consuming device to reduce the risk of weld breakage during falling of the battery and improve the falling safety of the battery.

[0005] In a first aspect, the present application provides a battery, comprising a shell, an electrode assembly and a buffer. The shell comprises a first shell and a second shell. The first shell comprises a bottom wall and a side wall. The side wall is located between the bottom wall and the second shell. The second shell is connected to the side wall. The electrode assembly is accommodated in the shell. The buffer is arranged between the side wall and the electrode assembly. The buffer comprises an expansion layer, and a surface of the expansion layer comprises a recess. The recess is recessed towards at least one of the side wall or the electrode assembly. By arranging the buffer between the side wall and the electrode assembly, the movement of the electrode assembly during falling of the battery can be inhibited. At the same time, the impact kinetic energy of the electrode assembly during falling can be buffered and absorbed by the recess on the surface of the expansion layer, the impact of the electrode assembly on the side wall is reduced, the risk of weld breakage is reduced, and the falling safety of the battery is improved.

[0006] In any one or more optional embodiments, the expansion layer comprises opposite first and second surfaces. The recess comprises a first recess on the first surface and a second recess on the second surface. The first recess is recessed towards the side wall. The second recess is recessed towards the electrode assembly. The first and second recesses can better provide buffering for the electrode assembly, absorb impact kinetic energy, reduce the impact of the electrode assembly on the side wall, and thus reduce the risk of weld breakage and improve the falling safety of the battery.

[0007] In any one or more optional embodiments, the first surface further comprises a first protrusion between adjacent first recesses. In this way, the electrode assembly can be better supported to inhibit the movement of the electrode assembly during falling of the battery, thereby reducing the impact of the electrode assembly on the side wall.

[0008] In any one or more optional embodiments, the first surface comprises a plurality of first recesses and a plurality of first protrusions. In this way, the impact of the electrode assembly can be better dispersed, the risk of weld seam blowout can be reduced, and the drop safety of the battery can be improved.

[0009] In any one or more optional embodiments, at least part of the first protrusions are in contact with the electrode assembly.

[0010] In any one or more optional embodiments, the second surface further comprises second protrusions, the second protrusions being located between adjacent second recesses. In this way, the electrode assembly can be better supported, and the movement of the electrode assembly during the drop of the battery can be better inhibited, so as to reduce the impact of the electrode assembly on the side wall.

[0011] In any one or more optional embodiments, the second surface comprises a plurality of second recesses and a plurality of second protrusions. In this way, the impact of the electrode assembly can be better dispersed, the risk of weld seam blowout can be reduced, and the drop safety of the battery can be improved.

[0012] In any one or more optional embodiments, at least part of the second protrusions are in contact with the side wall. In this way, the second protrusions can support the electrode assembly, better inhibit the movement of the electrode assembly during the drop of the battery, reduce the impact of the electrode assembly on the side wall, and thus reduce the risk of weld seam blowout.

[0013] In any one or more optional embodiments, the buffer comprises a plurality of expansion layers, at least part of the second recesses of one expansion layer being opposite to at least part of the first recesses of an adjacent expansion layer that is relatively close to the side wall. In this way, the buffer space can be increased, the electrode assembly can be better buffered, the impact kinetic energy can be absorbed, the impact of the electrode assembly on the side wall can be reduced, the risk of weld seam blowout can be further reduced, and the drop safety of the battery can be improved.

[0014] In any one or more optional embodiments, at least part of the second protrusions of the second surface of one expansion layer are in contact with the side wall.

[0015] In any one or more optional embodiments, at least part of the first protrusions of the first surface of one expansion layer are in contact with the electrode assembly.

[0016] In any one or more optional embodiments, along the first direction, the second recesses are located between adjacent first recesses. In this way, the second recesses and the first recesses are spaced apart along the first direction, which is conducive to better supporting and buffering the electrode assembly, better inhibiting the movement of the electrode assembly during the drop of the battery, reducing the impact of the electrode assembly on the side wall, and reducing the risk of weld seam blowout.

[0017] In any one or more optional embodiments, along the first direction, the second protrusions are located between adjacent first protrusions. In this way, the second protrusions and the first protrusions are spaced apart along the first direction, which is conducive to better supporting the electrode assembly, thereby better inhibiting the movement of the electrode assembly when the battery falls.

[0018] In any one or more optional embodiments, the expansion layer has a wavy structure. In this way, it is conducive to better supporting and buffering the electrode assembly, thereby better inhibiting the movement of the electrode assembly when the battery falls, reducing the impact of the electrode assembly on the side wall, and reducing the risk of the weld being punched open.

[0019] In any one or more optional embodiments, the side wall comprises a first side wall. The first side wall is located opposite the electrode assembly along a second direction. The buffer member is arranged between the first side wall and the electrode assembly, and the second direction is perpendicular to the first direction.

[0020] In any one or more optional embodiments, along the first direction, the distance between the lowest points of adjacent first recesses is H1, and 4mm≤H1≤12mm. In this way, better support and buffering can be provided for the electrode assembly, thereby better inhibiting the movement of the electrode assembly when the battery falls, reducing the impact of the electrode assembly on the side wall, and reducing the risk of the weld being punched open.

[0021] In any one or more optional embodiments, along the first direction, the distance between the lowest points of adjacent second recesses is H2, and 4mm≤H2≤12mm. In this way, better support and buffering can be provided for the electrode assembly, thereby better inhibiting the movement of the electrode assembly when the battery falls, reducing the impact of the electrode assembly on the side wall, and reducing the risk of the weld being punched open.

[0022] In any one or more optional embodiments, the first side wall and the electrode assembly have a first gap therebetween. Along the second direction, the size of the first gap is D, the depth of the first recess is d1, and 0.1D≤d1≤0.9D is satisfied. In this way, on the one hand, the first recess can provide sufficient buffering space to better buffer the impact of the electrode assembly and absorb impact kinetic energy, and on the other hand, the expansion layer has higher structural strength and can better support the electrode assembly, thereby better inhibiting the movement of the electrode assembly when the battery falls, and further reducing the impact of the electrode assembly on the side wall and the risk of the weld being punched open.

[0023] In any one or more optional embodiments, along the first direction, the length of the first side wall is L, and the length of the buffer member is l, and 0.4L≤l≤L is satisfied. In this way, it is conducive to better supporting and buffering the electrode assembly, inhibiting the movement of the electrode assembly when the battery falls, reducing the impact of the electrode assembly on the side wall, and further reducing the risk of the weld being punched open and improving the drop safety of the battery.

[0024] In any one or more optional embodiments, the side wall includes a first side wall extending along a first direction and a second side wall extending along a second direction. The first side wall has a length along the first direction that is less than a length of the second side wall along the second direction. The buffer is disposed between the first side wall and the electrode assembly. The second direction is perpendicular to the first direction. Under the same drop condition, the shorter side wall bears a greater force per unit length and has a higher risk of weld seam rupture. Disposing the buffer between the first side wall of the shorter length and the electrode assembly helps to reduce the risk of weld seam rupture and improve the drop safety of the battery.

[0025] In any one or more optional embodiments, the side wall further includes a third side wall opposite the first side wall along the second direction. The first side wall and the third side wall extend along the first direction. The second side wall connects the first side wall and the third side wall. The third side wall has a length along the first direction that is less than the length of the second side wall along the second direction. The first side wall has a length along the first direction that is less than or equal to the length of the third side wall along the first direction. The buffer is further disposed between the third side wall and the electrode assembly. In this way, the risk of weld seam rupture is further reduced, and the drop safety of the battery is improved.

[0026] In any one or more optional embodiments, the bottom wall has a shape including any one of a square, a rectangle, or an L shape.

[0027] In any one or more optional embodiments, the buffer includes at least one of an electrolyte-swelling adhesive tape or a heat-expanding adhesive tape.

[0028] In any one or more optional embodiments, the expansion layer has an expansion ratio of 100% to 500%.

[0029] In a second aspect, the present application provides a power-consuming device including the battery of any one of the above embodiments. Since the battery of the present application has high drop safety, the power-consuming device using the battery of the present application has good use safety. BRIEF DESCRIPTION OF DRAWINGS

[0030] FIG. 1 shows a structural schematic diagram of a battery in some embodiments of the present application.

[0031] FIG. 2 shows a structural schematic diagram of a first housing 10 in some embodiments of the present application.

[0032] FIG. 3 shows a partial structural schematic diagram of a battery in some embodiments of the present application.

[0033] FIG. 4 shows an enlarged schematic diagram of the partial structure in FIG. 3.

[0034] FIG. 5 shows a state schematic diagram of a buffer in some embodiments of the present application.

[0035] Fig. 6 shows a schematic view of the structure of the buffer in some embodiments of the present application.

[0036] Fig. 7 shows a schematic view of the structure of the buffer after expansion in the embodiment of Fig. 6.

[0037] Fig. 8 shows a schematic view of the structure of the buffer after expansion in another embodiment of the present application.

[0038] Fig. 9 shows a schematic view of an electrical device in some embodiments of the present application.

[0039] Main component symbol explanation:

[0040] Battery 100

[0041] First gap 101

[0042] Housing 10

[0043] Accommodation space 10a

[0044] First housing 11

[0045] Bottom wall 111

[0046] Side wall 112

[0047] First side wall 1121

[0048] Second side wall 1122

[0049] Third side wall 1123

[0050] Fourth side wall 1124

[0051] Fifth side wall 1125

[0052] Sixth side wall 1126

[0053] Second housing 12

[0054] Electrode assembly 20

[0055] Buffer 30

[0056] Recess 30a

[0057] First surface 31

[0058] Second surface 32

[0059] First recess 301

[0060] Second recess 302

[0061] First protrusion 303

[0062] Second protrusion 304

[0063] Expansion layer 310

[0064] Adhesive layer 320

[0065] Electric device 200

[0066] First direction X

[0067] Second direction Y

[0068] The following specific embodiments will further illustrate the present application in conjunction with the above figures. DETAILED DESCRIPTION

[0069] The following detailed description is presented in order to provide a basic understanding of the application. The various embodiments described above can be combined with each other in any manner.

[0070] When an element is referred to as being "on" another element, it can be directly on the other element or intervening elements can also be present. When an element is referred to as being "connected" to or "coupled" to another element, it can be directly connected to the other element or intervening elements can also be present.

[0071] It will be understood that the term "vertical" is used herein to describe a relationship of ideal state between two components. In actual production or use state, there can be a state similar to or equal to vertical between two components. For example, in combination with numerical description, vertical can refer to the included angle between two straight lines within the range of 90°±10°, vertical can also refer to the dihedral angle between two planes within the range of 90°±10°, and vertical can also refer to the included angle between a straight line and a plane within the range of 90°±10°. The two components described as "vertical" can not be absolute straight lines or planes, but can be approximately straight lines or planes, and as a whole, the overall extension direction is straight or planar, which can be considered as "straight line" or "plane".

[0072] Unless otherwise defined, the term "plurality" as used herein, specifically refers to two or more of the component when used to describe the number of components.

[0073] Some embodiments of the present application will be described in detail with reference to the drawings, which are given by way of illustration only and thus are not limitative of the present application. The following embodiments and features thereof can be combined with each other in any manner.

[0074] Referring to FIGS. 1-7, one embodiment of the present application provides a battery 100, which includes a housing 10 and an electrode assembly 20 received in the housing 10.

[0075] In some embodiments, the housing 10 includes a first housing 11 and a second housing 12. The first housing 11 includes a bottom wall 111 and a side wall 112, and the side wall 112 is located between the bottom wall 111 and the second housing 12. The second housing 12 is connected to the side wall 112.

[0076] In some embodiments, the side wall 112 is connected to the bottom wall 111 and forms a receiving space 10a, and the electrode assembly 20 is arranged in the receiving space 10a. The second housing 12 is connected to the side wall 112 and seals the receiving space 10a.

[0077] In some embodiments, the bottom wall 111 and the side wall 112 are integrally formed, for example, by punching.

[0078] In some embodiments, the second shell 12 is welded to the side wall 112. A weld is formed between the side wall 112 and the second shell 12. In some embodiments, the shell 10 can be selected from a steel shell, an aluminum shell, and the like.

[0079] In some embodiments, the battery 100 comprises a buffer 30 disposed between the side wall 112 and the electrode assembly 20. The buffer 30 comprises an expansion layer 310, a surface of the expansion layer 310 comprises a recess 30a, the recess 30a is recessed towards at least one of the side wall 112 or the electrode assembly 20.

[0080] By disposing the buffer 30 between the side wall 112 and the electrode assembly 20, the battery 100 can inhibit the movement of the electrode assembly 20 when the battery 100 falls. At the same time, the recess 30a formed on the surface of the expansion layer 310 can buffer and absorb the impact kinetic energy of the electrode assembly 20 when the battery 100 falls, reduce the impact of the electrode assembly 20 on the side wall 112, and further reduce the risk of the weld being broken open, thereby improving the drop safety of the battery 100.

[0081] In some embodiments, the shape of the bottom wall 111 comprises any one of a square, a rectangle, or an L shape.

[0082] In some embodiments, the battery 100 comprises an electrolyte, the electrolyte is disposed in the shell 10. When the expansion layer 310 in the buffer 30 absorbs the electrolyte and expands, the expansion layer 310 fills the gap between the side wall 112 and the electrode assembly 20, thereby facilitating the inhibition of the movement of the electrode assembly 20 when the battery 100 falls.

[0083] In some embodiments, when the buffer 30 is heated, the expansion layer 310 in the buffer 30 expands and fills the gap between the side wall 112 and the electrode assembly 20, thereby facilitating the inhibition of the movement of the electrode assembly 20 when the battery 100 falls.

[0084] In some embodiments, the buffer 30 comprises at least one of an electrolyte swelling tape or a heat-expanding tape.

[0085] In some embodiments, the expansion ratio of the expansion layer 310 is 100% to 500%, which is conducive to better buffering the electrode assembly 20 and absorbing the impact kinetic energy, thereby reducing the impact of the electrode assembly 20 on the side wall 112 and reducing the risk of the weld being broken open.

[0086] Alternatively, the expansion ratio of the expansion layer 310 can be any one of 100%, 120%, 140%, 160%, 180%, 200%, 220%, 240%, 260%, 280%, 300%, 320%, 340%, 360%, 380%, 400%, 420%, 440%, 460%, 480%, 500%, and a range formed by any two of the above.

[0087] Referring to FIG. 5, FIG. 6 and FIG. 7, in some embodiments, the buffer 30 comprises an adhesive layer 320. In assembling the battery 100, the buffer 30 can be pre-adhered to the side wall 112 through the adhesive layer 320, and then the electrode assembly 20 is assembled into the first shell 11. In order to facilitate the entry of the electrode assembly 20 into the shell, there is a gap between the buffer 30 and the electrode assembly 20, and when the buffer 30 swells, the buffer 30 fills the gap between the side wall 112 and the electrode assembly 20. In some embodiments, when the electrolyte is injected into the shell 10 of the battery 100, the swelling layer 310 in the buffer 30 swells after absorbing the electrolyte, and at the same time, the adhesive layer 320 in the buffer 30 loses adhesion with the side wall 112 under the action of the electrolyte and dissolves in the electrolyte, thereby promoting the formation of a concave-convex structure on the surface of the swelling layer 310. In some embodiments, during the heat treatment process for drying water in the battery 100 before electrolyte injection, the swelling layer 310 in the buffer 30 swells under heat, and at the same time, the adhesive layer 320 in the buffer 30 loses adhesion under heat, thereby promoting the formation of a concave-convex structure on the surface of the swelling layer 310.

[0088] In some embodiments, the buffer 30 is adhered to the side wall 112, and the adhesion strength F1 between the buffer 30 and the side wall 112 is F1≥1N / mm, which is beneficial to reliably pre-set the buffer 30 on the side wall 112.

[0089] In some embodiments, the buffer 30 is adhered to the electrode assembly 20, and the adhesion strength F2 between the buffer 30 and the electrode assembly 20 is F2≥1N / mm, which is beneficial to reliably pre-set the buffer 30 on the end face of the electrode assembly 20, and facilitate the entry of the electrode assembly 20 into the shell.

[0090] Referring to FIG. 7, in some embodiments, the swelling layer 310 comprises a first surface 31 and a second surface 32 opposite to each other. The recess 30a comprises a first recess 301 on the first surface 31, and the first recess 301 is recessed towards the side wall 112, which is beneficial to buffer and absorb impact kinetic energy, reduce the impact of the electrode assembly 20 on the side wall 112, and reduce the risk of weld breakage.

[0091] In some embodiments, the recess 30a comprises a second recess 302 on the second surface 32, and the second recess 302 is recessed towards the electrode assembly 20. The second recess 302 can better provide support and buffering for the electrode assembly 20, further absorb impact kinetic energy, reduce the impact of the electrode assembly 20 on the side wall 112, and further reduce the risk of weld breakage, thereby improving the drop safety of the battery 100.

[0092] In some embodiments, the first surface 31 further comprises a plurality of first protrusions 303, the first protrusions 303 being located between adjacent first recesses 301. In this way, the electrode assembly 20 can be better supported to inhibit movement of the electrode assembly 20 when the battery 100 is dropped, thereby reducing the impact of the electrode assembly 20 on the side wall 112.

[0093] In some embodiments, the first surface 31 comprises a plurality of first recesses 301 and a plurality of first protrusions 303. In this way, the impact of the electrode assembly 20 can be better dispersed, the risk of weld breakage can be reduced, and the drop safety of the battery 100 can be improved.

[0094] In some embodiments, at least part of the first protrusions 303 are in contact with the electrode assembly 20.

[0095] In some embodiments, the second surface 32 further comprises a plurality of second protrusions 304, the second protrusions 304 being located between adjacent second recesses 302. In this way, the electrode assembly 20 can be better supported to inhibit movement of the electrode assembly 20 when the battery 100 is dropped, thereby reducing the impact of the electrode assembly 20 on the side wall 112.

[0096] In some embodiments, the second surface 32 comprises a plurality of second recesses 302 and a plurality of second protrusions 304. In this way, the impact of the electrode assembly 20 can be better dispersed, the risk of weld breakage can be reduced, and the drop safety of the battery 100 can be improved.

[0097] In some embodiments, at least part of the second protrusions 304 are in contact with the side wall 112. In this way, the second protrusions 304 can support the electrode assembly 20, better inhibit movement of the electrode assembly 20 when the battery 100 is dropped, reduce the impact of the electrode assembly 20 on the side wall 112, and thereby reduce the risk of weld breakage.

[0098] In some embodiments, the plurality of first recesses 301 are spaced apart along the first direction X on the first surface 31.

[0099] In some embodiments, the plurality of first protrusions 303 are spaced apart along the first direction X on the first surface 31.

[0100] In some embodiments, the plurality of second recesses 302 are spaced apart along the first direction X on the second surface 32.

[0101] In some embodiments, the plurality of second protrusions 304 are spaced apart along the first direction X on the second surface 32.

[0102] In some embodiments, along the first direction X, the second recesses 302 are located between adjacent first recesses 301.

[0103] In some embodiments, along the first direction X, the first concave portion 301 is located between adjacent second concave portions 302.

[0104] In some embodiments, along the first direction X, the first convex portion 303 is located between adjacent second convex portions 304. In this way, it is beneficial to better provide support and cushion for the electrode assembly 20, so as to better inhibit the movement of the electrode assembly 20 when the battery 100 falls, reduce the impact of the electrode assembly 20 on the side wall 112, and reduce the risk of weld breakage.

[0105] In some embodiments, along the first direction X, the second convex portion 304 is located between adjacent first convex portions 303. In this way, the second convex portion 304 and the first convex portion 303 are spaced apart along the first direction X, which is beneficial to better provide support for the electrode assembly 20, so as to better inhibit the movement of the electrode assembly 20 when the battery 100 falls.

[0106] In some embodiments, the expansion layer 310 has a wavy structure, so as to better provide support and cushion for the electrode assembly 20 and reduce the risk of weld breakage.

[0107] Please refer to FIGS. 7 and 8, in some embodiments, the buffer 30 includes a plurality of expansion layers 310. Each expansion layer 310 independently includes a first concave portion 301, a second concave portion 302, a first convex portion 303, and a second convex portion 304. Please further refer to FIG. 8, there is a gap between the expansion layers 310. In this way, the buffer space can be increased, the electrode assembly 20 can be better cushioned, the impact kinetic energy can be absorbed, the impact of the electrode assembly 20 on the side wall 112 can be reduced, and thus the risk of weld breakage can be reduced, and the drop safety of the battery 100 can be improved.

[0108] Please continue to refer to FIG. 8, in some embodiments, at least part of the second concave portion 302 of an expansion layer 310 is opposite to at least part of the first concave portion 301 of the adjacent expansion layer 310 close to the side wall 112. In this way, the buffer space can be further increased, the electrode assembly 20 can be better cushioned, the impact kinetic energy can be absorbed, the impact of the electrode assembly 20 on the side wall 112 can be reduced, and thus the risk of weld breakage can be reduced, and the drop safety of the battery 100 can be improved.

[0109] Please refer to FIGS. 2-3, in some embodiments, the side wall 112 includes a first side wall 1121, and the first side wall 1121 is opposite to the electrode assembly 20 along a second direction Y. The buffer 30 is arranged between the first side wall 1121 and the electrode assembly 20. The first direction X is perpendicular to the second direction Y.

[0110] In some embodiments, referring to FIG. 7, along the first direction X, the distance between the lowest points of adjacent first recesses 301 is H1, 4mm≤H1≤12mm. In this way, the electrode assembly 20 can be provided with better support and cushioning, thereby better inhibiting the movement of the electrode assembly 20 when the battery 100 falls, reducing the impact of the electrode assembly 20 on the side wall 112, and reducing the risk of weld tearing. Alternatively, H1 can be any one of 4mm, 5mm, 6mm, 7mm, 8mm, 9mm, 10mm, 11mm, 12mm or a range consisting of any two of them.

[0111] In some embodiments, along the first direction X, the distance between the lowest points of adjacent second recesses 302 is H2, 4mm≤H2≤12mm. In this way, the electrode assembly 20 can be provided with better support and cushioning, thereby better inhibiting the movement of the electrode assembly 20 when the battery 100 falls, reducing the impact of the electrode assembly 20 on the side wall 112, and reducing the risk of weld tearing. Alternatively, H2 can be any one of 4mm, 5mm, 6mm, 7mm, 8mm, 9mm, 10mm, 11mm, 12mm or a range consisting of any two of them.

[0112] Referring to FIGS. 4-7, in some embodiments, the first side wall 1121 and the electrode assembly 20 have a first gap 101 therebetween, along the second direction Y, the size of the first gap 101 is D, the depth of the first recess 301 is d1, 0.1D≤d1≤0.9D. In this way, on the one hand, the first recess 301 can provide sufficient cushioning space to better cushion the impact of the electrode assembly 20 and absorb impact kinetic energy, on the other hand, the expansion layer 310 has higher structural strength and can better support the electrode assembly 20, thereby better inhibiting the movement of the electrode assembly 20 when the battery 100 falls, thereby reducing the impact of the electrode assembly 20 on the side wall 112 and reducing the risk of weld tearing.

[0113] In some embodiments, D≥0.3mm, in this way, it is convenient to install the electrode assembly 20 into the shell.

[0114] In some embodiments, along the second direction Y, the depth of the second recess 302 is d2, 0.1D≤d2≤0.9D. In this way, on the one hand, the second recess 302 can provide sufficient cushioning space to better cushion the impact of the electrode assembly 20 and absorb impact kinetic energy, on the other hand, the expansion layer 310 has higher structural strength and can better support the electrode assembly 20, thereby better inhibiting the movement of the electrode assembly 20 when the battery 100 falls, thereby reducing the impact of the electrode assembly 20 on the side wall 112 and reducing the risk of weld tearing.

[0115] Referring to FIGS. 4-7, in some embodiments, the length of the first side wall 1121 along the first direction X is L, the length of the buffer 30 is l, and 0.4L≤l≤L. In this way, the electrode assembly 20 can be better supported and buffered, the movement of the electrode assembly 20 when the battery 100 falls can be inhibited, the impact of the electrode assembly 20 on the side wall 112 can be reduced, the risk of the weld being broken open can be reduced, and the drop safety of the battery 100 can be improved.

[0116] Referring to FIGS. 2 and 3, in some embodiments, the side wall 112 includes a first side wall 1121 extending along the first direction X and a second side wall 1122 extending along the second direction Y, the length L of the first side wall 1121 along the first direction X is less than the length w2 of the second side wall 1122 along the second direction Y, and the buffer 30 is arranged between the first side wall 1121 and the electrode assembly 20. Under the same drop condition, the shorter side wall 112 bears a greater force per unit length, and the risk of the weld being broken open is also higher. Arranging the buffer 30 between the first side wall 1121, which is shorter in length, and the electrode assembly 20 can reduce the risk of the weld being broken open and improve the drop safety of the battery 100.

[0117] Referring to FIG. 3, in some embodiments, when the bottom wall 111 is L-shaped, the side wall 112 further includes a third side wall 1123, and the first side wall 1121 and the third side wall 1123 are oppositely arranged along the second direction Y. The third side wall 1123 extends along the first direction X. The second side wall 1122 connects the first side wall 1121 and the third side wall 1123. The length w3 of the third side wall 1123 along the first direction X is less than the length w2 of the second side wall 1122 along the second direction Y, and the length L of the first side wall 1121 along the first direction X is less than or equal to the length w3 of the third side wall 1123 along the first direction X. The buffer 30 is also arranged between the third side wall 1123 and the electrode assembly 20. In this way, the risk of the weld being broken open can be further reduced, and the drop safety of the battery 100 can be improved.

[0118] In some embodiments, 0.4w3≤l≤w3. In this way, the electrode assembly 20 can be better supported and buffered, the movement of the electrode assembly 20 when the battery 100 falls can be inhibited, the impact of the electrode assembly 20 on the side wall 112 can be reduced, the risk of the weld being broken open can be reduced, and the drop safety of the battery 100 can be improved.

[0119] In some embodiments, when the bottom wall 111 is rectangular, the length w3 of the third side wall 1123 along the first direction X is less than the length w2 of the second side wall 1122 along the second direction Y, and the length L of the first side wall 1121 along the first direction X is equal to the length w3 of the third side wall 1123 along the first direction X. The buffer 30 is arranged between the first side wall 1121 and the electrode assembly 20, and the buffer 30 is also arranged between the third side wall 1123 and the electrode assembly 20.

[0120] Referring to FIG. 3, in some embodiments, the side wall 112 comprises a fourth side wall 1124, the first side wall 1121, the fourth side wall 1124 and the third side wall 1123 are arranged along the second direction Y. The fourth side wall 1124 extends along the first direction X. The length w4 of the fourth side wall 1124 along the first direction X is less than the length L of the first side wall 1121 along the first direction X, and the length w4 of the fourth side wall 1124 along the first direction X is less than the length w3 of the third side wall 1123 along the first direction X. The buffer 30 is also provided between the fourth side wall 1124 and the electrode assembly 20, so as to further reduce the risk of weld breakage.

[0121] In some embodiments, 0.4w4≤l≤w4. In this way, it is beneficial to better support and buffer the electrode assembly 20, inhibit the movement of the electrode assembly 20 when the battery 100 falls, reduce the impact of the electrode assembly 20 on the side wall 112, thereby reducing the risk of weld breakage and improving the drop safety of the battery 100.

[0122] The application will be further described below through specific embodiments.

[0123] Take an L-shaped steel shell lithium ion battery as an example to perform a drop experiment, wherein the positive electrode material of the lithium ion battery is lithium cobaltate, and the negative electrode material is graphite; the length L of the first side wall 1121 is 46 mm, the length w2 of the second side wall 1122 is 78 mm, and the length w3 of the third side wall 1123 is 56 mm; the length w4 of the fourth side wall 1124 is 10 mm; the length w5 of the fifth side wall 1125 is 61 mm; and the length w6 of the sixth side wall 1126 is 17 mm. The height of the side wall 112 is 4.5 mm; and the interval D is 0.3 mm.

[0124] In Example 1-10, the buffer 30 is pasted at the first side wall 1121 and the third side wall 1123, and the thickness of the adhesive layer 320 in the buffer 30, the thickness of the expansion layer 310, the number of layers of the expansion layer 310 / adhesive layer 320 (each layer of the expansion layer 310 is connected by the adhesive layer 320), the length l1 of the buffer 30 at the first side wall 1121, and the length l3 of the buffer 30 at the third side wall 1123 are adjusted according to Table 1. The material of the adhesive layer 320 is an electrolyte-insensitive acrylic ester pressure-sensitive adhesive; and the material of the expansion layer 310 is a cross-linked polyacrylic acid resin, wherein the adhesive layer 320 is dissolved and loses adhesion after liquid injection, and the expansion layer 310 expands after absorbing electrolyte.

[0125] In Comparative Example 1, no buffer 30 is provided at the first side wall 1121 and the third side wall 1123.

[0126] The difference between Comparative Example 2 and Example 3 is that the material of the adhesive layer 320 is changed to electrolyte-resistant SIS (styrene-isoprene-styrene copolymer) glue. After liquid injection, the adhesive layer 320 will not lose adhesion, allowing the expansion layer 310 to expand uniformly in the thickness direction, thereby densely filling the gap between the shell side wall 112 and the electrode assembly 20.

[0127] Each group of 20 batteries was subjected to a drop pass rate comparison experiment. The batteries were tested in the order of the first side wall 1121 and the third side wall 1123 facing down, with each side dropping 3 times at a drop height of 1.8 m. After the drop, it was observed whether the shell 10 was broken or leaked, and the number of batteries with broken or leaked shells 10 was counted.

[0128] Table 1

[0129] As can be seen from the above table, according to Comparative Examples 1-2 and Examples 1-10, by providing the buffer member 30 at the first side wall 1121 and the third side wall 1123, and by the recess 30a formed on the surface of the expansion layer 310, the impact kinetic energy when the electrode assembly 20 drops can be buffered and absorbed, reducing the impact of the electrode assembly 20 on the first side wall 1121 and the third side wall 1123, thereby reducing the risk of weld breakage and improving the drop safety of the battery 100.

[0130] As can be seen from Examples 1-3 and Comparative Example 2, the expansion layer 310 with the recess structure has a better effect of buffering and absorbing the impact kinetic energy when the electrode assembly 20 drops, and the number of dropped batteries is lower.

[0131] As can be seen from Example 2 and Examples 4-5, when multiple expansion layers 310 are provided, the second recess 302 and the first recess 301 of the adjacent two expansion layers 310 can be opposite, thereby better buffering the electrode assembly 20 and further reducing the risk of weld breakage.

[0132] Referring to FIG. 9, the application also provides an electric device 200 using the above battery 100.

[0133] In some embodiments, the electric device 200 of the application can be, but is not limited to, an electronic device, a drone, a backup power supply, an electric vehicle, an electric motorcycle, an electric assist bicycle, an electric tool, etc.

[0134] Those skilled in the art should understand that the above examples are only used to illustrate the application, and are not used as a limitation on the application. Any appropriate changes and variations made to the above examples within the spirit and scope of the application fall within the scope of the disclosure.

Claims

1. A battery, characterized in that, include: The housing includes a first housing and a second housing, the first housing includes a bottom wall and a side wall, the side wall is located between the bottom wall and the second housing, and the second housing is connected to the side wall; Electrode assembly, housed within the housing; A buffer element is disposed between the sidewall and the electrode assembly. The buffer element includes an expansion layer, the surface of which includes a recess facing at least one of the sidewall or the electrode assembly.

2. The battery as described in claim 1, characterized in that, The expansion layer includes a first surface and a second surface opposite to each other, and the recess includes a first recess located on the first surface and a second recess located on the second surface, the first recess being recessed toward the sidewall and the second recess being recessed toward the electrode assembly.

3. The battery as described in claim 2, characterized in that, At least one of the following conditions must be met: (1) The first surface further includes a first protrusion, which is located between adjacent first recesses; (2) The second surface further includes a second protrusion located between adjacent second recesses.

4. The battery as described in claim 3, characterized in that, At least one of the following conditions must be met: (1) The first surface includes a plurality of first recesses and a plurality of first protrusions; (2) At least a portion of the first protrusion is in contact with the electrode assembly; (3) The second surface includes a plurality of second recesses and a plurality of second protrusions; (4) At least a portion of the second protrusion is in contact with the sidewall; (5) Along the first direction, the second recess is located between adjacent first recesses; (6) Along the first direction, the second protrusion is located between adjacent first protrusions; (7) The expansion layer has a wavy structure.

5. The battery as described in claim 3, characterized in that, The buffer includes multiple expansion layers.

6. The battery as described in claim 5, characterized in that, At least one of the following conditions must be met: (1) At least a portion of the second recess of the expansion layer is opposite to at least a portion of the first recess of an adjacent expansion layer that is relatively close to the sidewall; (2) At least a portion of the second protrusion on the second surface of the expansion layer is in contact with the sidewall; (3) At least a portion of the first protrusion on the first surface of the expansion layer is in contact with the electrode assembly.

7. The battery as described in claim 4, characterized in that, The sidewall includes a first sidewall, which is disposed opposite to the electrode assembly along a second direction. The buffer is disposed between the first sidewall and the electrode assembly. The second direction is perpendicular to the first direction, and at least one of the following conditions is satisfied: (1) Along the first direction, the distance between the lowest points of adjacent first recesses is H1, 4mm≤H1≤12mm; (2) Along the first direction, the distance between the lowest points of adjacent second concave portions is H2, 4mm≤H2≤12mm; (3) There is a first gap between the first sidewall and the electrode assembly. Along the second direction, the size of the first gap is D, and the depth of the first recess is d1, satisfying that 0.1D≤d1≤0.9D; (4) Along the first direction, the length of the first sidewall is L and the length of the buffer is l, satisfying that 0.4L≤l≤L.

8. The battery as claimed in claim 1, characterized in that, The sidewall includes a first sidewall extending along a first direction and a second sidewall extending along a second direction. The length of the first sidewall along the first direction is less than the length of the second sidewall along the second direction. The buffer is disposed between the first sidewall and the electrode assembly. The second direction is perpendicular to the first direction.

9. The battery as claimed in claim 8, characterized in that, The sidewall also includes a third sidewall opposite to the first sidewall along the second direction. The first sidewall and the third sidewall extend along the first direction. The second sidewall connects the first sidewall and the third sidewall. The length of the third sidewall along the first direction is less than the length of the second sidewall along the second direction. The length of the first sidewall along the first direction is less than or equal to the length of the third sidewall along the first direction. The buffer is also disposed between the third sidewall and the electrode assembly.

10. The battery as claimed in any one of claims 1 to 9, characterized in that, At least one of the following conditions must be met: (1) The shape of the bottom wall includes any one of a square, a rectangle or an L-shape; (2) The buffer includes at least one of electrolyte-swellable tape or thermal expansion tape; (3) The expansion ratio of the expansion layer is 100% to 500%.

11. An electrical appliance, characterized in that, Includes the battery as described in any one of claims 1 to 10.

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