Battery

Abstract

The utility model provides a battery which comprises a shell and a pressure relief assembly, the shell comprises a first side wall, the first side wall is provided with a first through hole, and the first through hole penetrates through two opposite surfaces of the first side wall along a first direction; the pressure relief assembly comprises a connecting piece, a sealing piece and a bonding layer, the connecting piece comprises a second connecting part and a first connecting part which are connected with each other, the first connecting part is welded to the first side wall, the second connecting part is provided with a second through hole, the projection of the second through hole on the first side wall is at least partially overlapped with the first through hole, and the bonding layer is located between the connecting piece and the sealing piece. The sealing piece is bonded to the second connecting part through the bonding layer and blocks the first through hole and the second through hole. The battery provided by the utility model is relatively low in cost and relatively high in safety.

Description

Technical Field

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

[0002] Batteries are a widely used electrochemical energy storage device. Using batteries as an energy source can obtain stable voltage and current, and they play a great role in all aspects of modern social life.

[0003] In the related art, the battery may include a metal shell, a battery cell, a tab and a pole. The tab may include a positive tab and a negative tab. Both the positive tab and the negative tab are connected to the battery cell to draw out the current of the battery cell. The pole is connected to the positive tab to draw out the current of the positive tab and then connect it to the device to be powered. The negative tab may be connected to the metal shell to draw out the current of the negative tab through the metal shell. Since the wall thickness of the metal shell is relatively thin, an adapter may be welded on the metal shell and then connected to the device to be powered through the adapter. In addition, the battery also needs to be provided with an explosion-proof structure to relieve pressure when the pressure inside the battery is abnormal, thereby preventing the battery from exploding.

[0004] However, the battery cost in the related art is high. Utility Model Content

[0005] Based on this, the present application provides a battery with lower cost and higher safety.

[0006] The battery provided in the present application comprises a housing and a pressure relief assembly, wherein the housing comprises a first side wall, the first side wall has a first through hole, and the first through hole penetrates two opposite sides of the first side wall along a first direction;

[0007] The pressure relief assembly includes a connecting piece, a sealing piece and an adhesive layer. The connecting piece is welded to the first side wall. The connecting piece includes a first connecting portion and a second connecting portion that are connected to each other. The first connecting portion and the second connecting portion extend along a second direction. The second connecting portion has a second through hole. The projection of the second through hole on the first side wall at least partially overlaps with the first through hole. The first connecting portion and the first side wall are welded. The adhesive layer is located between the connecting piece and the sealing piece. The sealing piece is bonded to the second connecting portion through the adhesive layer. The sealing piece blocks the first through hole and the second through hole.

[0008] In a possible implementation, the battery cell is disposed in the housing, and the battery cell has a first pole lug and a second pole lug with opposite polarities;

[0009] The second pole tab is connected to the housing, and a projection of the second pole tab on the first side wall and a projection of the first connecting portion on the first side wall at least partially overlap.

[0010] In a possible implementation, the battery includes a protection plate located on the first side wall, the protection plate includes a first pin, and the first pin is connected to the first connecting portion.

[0011] In a possible implementation, a portion where the connecting piece and the first side wall overlap each other has a welding area, and the welding area includes a welding mark;

[0012] The welding mark includes at least one of a first welding mark, a second welding mark and a third welding mark, the first welding mark connects the first side wall and the second connection part, the second welding mark connects the first side wall and the first connection part, and the third welding mark connects the first connection part and the first pin.

[0013] In a possible implementation, along the second direction, the distance between the first weld mark and the third weld mark is greater than the distance between the second weld mark and the third weld mark.

[0014] In a possible implementation, the projection shape of the first weld mark on the first side wall is a closed ring, and the first weld mark is arranged around the circumference of the first through hole;

[0015] And / or, the projection shape of the second weld mark on the first side wall is a dot shape or a line shape;

[0016] And / or, the projection shape of the third weld mark on the first side wall is dot-shaped or line-shaped.

[0017] In a possible implementation, a gap is left between the projection of the second weld mark on the first side wall and the projection of the third weld mark on the first side wall, and / or,

[0018] A gap is left between the projection of the first weld mark on the first side wall and the projection of the third weld mark on the first side wall.

[0019] In a possible implementation, the first weld mark runs through two opposite sides of the second connecting portion, and at least a portion of the first weld mark is located on the first side wall;

[0020] and / or, the difference between the outer diameter of the first weld mark and the inner diameter of the first weld mark is greater than or equal to 0.05 mm;

[0021] And / or, a ratio of an extension dimension of the first weld mark located on the first side wall along the first direction to a thickness of the first side wall is greater than or equal to 0.01.

[0022] In one possible implementation, the third weld mark passes through two opposite sides of the first connecting portion, at least part of the third weld mark is located on the first side wall, and the ratio of the extension dimension of the third weld mark located on the first side wall along the first direction to the thickness of the first side wall is less than or equal to 0.5.

[0023] In a possible implementation manner, the thickness of the first connecting portion is greater than or equal to the thickness of the second connecting portion.

[0024] In a possible implementation manner, the thickness of the first connecting portion is greater than or equal to the thickness of the first side wall, and the thickness of the second connecting portion is less than the thickness of the first side wall.

[0025] In one possible implementation, the ratio of the thickness of the first connecting portion to the thickness of the first side wall is greater than or equal to 1 and less than or equal to 1.5; and / or the ratio of the thickness of the second connecting portion to the thickness of the first side wall is greater than or equal to 0.3 and less than or equal to 0.9.

[0026] In one possible implementation, the ratio of the extension dimension of the second through hole along the second direction to the extension dimension of the second through hole along the third direction is greater than 1, and the ratio of the extension dimension of the second through hole along the third direction to the extension dimension of the first through hole along the third direction is less than or equal to 2.

[0027] In a possible implementation manner, the shapes of the adhesive layer and the sealing sheet match, and the projections of the sealing sheet and the adhesive layer on the connecting sheet both cover the second through hole.

[0028] In a possible implementation, a difference between an extension dimension of the adhesive layer along the second direction and an extension dimension of the second through hole along the second direction is greater than or equal to 0.05 mm;

[0029] And / or, a difference between an extension dimension of the adhesive layer along the third direction and an extension dimension of the second through hole along the third direction is greater than or equal to 0.05 mm.

[0030] In a possible implementation manner, the adhesive layer has a third through hole, the first through hole, the second through hole and the third through hole are connected in sequence, and the shape of the third through hole matches that of the second through hole.

[0031] In a possible implementation, the sealing sheet has a first notch groove, and the ratio of the thickness depth of the bottom wall of the first notch groove to the thickness of the sealing sheet is greater than or equal to 0.1 and less than or equal to 0.5;

[0032] And / or, the width of the first notch groove is greater than or equal to 0.05 mm and less than or equal to 0.5 mm.

[0033] In a possible implementation, the melting point of the adhesive layer is greater than or equal to 80° C. and less than or equal to 180° C.

[0034] In a possible implementation, the battery of the present application also includes a battery cell and a pole, the battery cell is arranged in a shell, the battery cell has a first pole ear and a second pole ear with opposite polarities, the first side wall has a fourth through hole, the pole is inserted into the shell through the fourth through hole to be connected to the first pole ear, and the second pole ear is connected to the shell.

[0035] In a possible implementation, the housing further includes a second side wall, the second side wall has a second notch groove, the second notch groove extends along an arc line, and a ratio of a thickness of a bottom wall of the second notch groove to a thickness of the second side wall is greater than or equal to 0.1 and less than or equal to 0.5;

[0036] And / or, the width of the second scoring groove is greater than or equal to 0.05 mm and less than or equal to 0.5 mm.

[0037] In a possible implementation, the first side wall and the second side wall are located on two adjacent sides of the housing;

[0038] The second notch groove is located on a side of the second side wall close to the first side wall.

[0039] The battery provided by the present application includes a shell and a pressure relief component, the shell includes a first side wall, the first side wall includes a first through hole, the pressure relief component includes a connecting piece, an adhesive layer and a sealing piece, the connecting piece includes a first connecting part and a second connecting part, the second connecting part includes a second through hole, the first through hole is provided for electrolyte injection and battery pressure relief, the second connecting part is provided for connecting with the first side wall to improve the connection strength between the adhesive layer and the first side wall, the second through hole is provided at the second connecting part to avoid the second connecting part blocking the first through hole, the adhesive layer is provided for connecting the sealing piece and the second connecting part, so that the sealing piece blocks the first through hole and the second through hole, and the adhesive layer is melted when the temperature of the battery reaches a preset temperature, so that the sealing piece is separated from the second connecting part, so that the first through hole and the second through hole are exposed for battery pressure relief, the first connecting part is provided for locally thickening the first side wall to improve the connection strength between the first side wall and the protective plate, and the first connecting part and the second connecting part are integrally formed to simplify the processing process of the two, thereby reducing the cost of the battery. Therefore, the battery provided by the present application has low cost and high safety.

[0040] In addition to the technical problems solved by the embodiments of the present application described above, the technical features that constitute the technical solutions, and the beneficial effects brought about by the technical features of these technical solutions, other technical problems that can be solved by the battery provided by the present application, other technical features included in the technical solutions, and the beneficial effects brought about by these technical features will be further described in detail in the specific implementation methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0042] Figure 1 Schematic diagram of the structure of the battery provided in the embodiment of the present application Figure 1 ;

[0043] Figure 2 for Figure 1Exploded diagram of

[0044] Figure 3 Schematic diagram of the structure of the battery provided in the embodiment of the present application Figure 2 ;

[0045] Figure 4 for Figure 3 AA section view;

[0046] Figure 5 A schematic diagram of the structure of the housing, pressure relief assembly and pole in the battery provided in the embodiment of the present application;

[0047] Figure 6 A schematic diagram of the structure of a pressure relief assembly in a battery provided in an embodiment of the present application;

[0048] Figure 7 for Figure 6 Exploded diagram of

[0049] Figure 8 A schematic diagram of the structure of a connecting piece in a battery provided in an embodiment of the present application;

[0050] Fig. 9 A schematic diagram of the structure of a sealing sheet in a battery provided in an embodiment of the present application;

[0051] Fig.10 A schematic diagram of the structure of a battery housing provided in an embodiment of the present application.

[0052] Description of reference numerals:

[0053] 100-housing; 110-first side wall; 111-first through hole; 112-fourth through hole; 120-second side wall; 121-second notch groove; 200-pressure relief assembly; 210-connecting plate; 211-first connecting portion; 212-second connecting portion; 2121-second through hole; 220-sealing plate; 221-first notch groove; 230-adhesive layer; 231-third through hole; 300-battery cell; 400-pole. DETAILED DESCRIPTION

[0054] In order to make the purpose, technical scheme and advantages of the present application clearer, the technical scheme in the embodiment of the present application will be described in more detail below in conjunction with the drawings in the preferred embodiments of the present application. In the drawings, the same or similar reference numerals throughout represent the same or similar parts or parts with the same or similar functions. The described embodiments are part of the embodiments of the present application, not all of the embodiments. The embodiments described below with reference to the drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limitations on the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present application. The embodiments of the present application are described in detail below in conjunction with the drawings.

[0055] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, or it can be an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0056] In the description of the present application, it should be understood that the terms "upper", "lower", "front", "back", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships, are orientations or positional relationships based on the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0057] The terms "first", "second", "third" (if any) in the specification and claims of this application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the application described herein can be implemented in an order other than those illustrated or described herein, for example.

[0058] In addition, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, for example, a process, method, system, product, or display comprising a series of steps or elements is not necessarily limited to those steps or elements explicitly listed, but may include other steps or elements not explicitly listed or inherent to such process, method, product, or display.

[0059] In the related art, the battery may include a metal shell, a battery cell, a pole ear and a pole column. The pole ear may include a positive pole ear and a negative pole ear. The positive pole ear and the negative pole ear are both connected to the battery cell to lead out the current of the battery cell. The pole column is connected to the positive pole ear to lead out the current of the positive pole ear and then connect to the device to be powered. The negative pole ear may be connected to the metal shell to lead out the current of the negative pole ear through the metal shell. Since the wall thickness of the metal shell is relatively thin, an adapter plate may be welded on the metal shell, and then connected to the device to be powered through the adapter plate. In addition, the battery also needs to be provided with an explosion-proof structure to relieve pressure when the pressure inside the battery is abnormal, thereby preventing the battery from exploding. The explosion-proof structure may include a welding sheet, a glue layer and a sealing sheet. The welding sheet is welded to the metal shell to improve the connection strength between the adhesive layer and the metal shell. The glue layer is bonded between the welding sheet and the sealing sheet. When the battery temperature is high, the glue layer will melt due to heat, thereby causing the sealing sheet to be disconnected from the welding sheet, thereby releasing the pressure inside the battery.

[0060] However, the applicant found that when manufacturing the battery, it is necessary to process the welding plate and the adapter plate separately, and then weld the welding plate and the adapter plate to the metal shell respectively. This process requires at least four steps, which increases the cost of the battery.

[0061] In view of this, an embodiment of the present application provides a battery, wherein a connecting piece is connected to an outer shell, the connecting piece includes a first connecting portion and a second connecting portion, an adhesive layer is connected between the second connecting portion and a sealing piece, the second connecting portion can improve the connection strength between the adhesive layer and the outer shell, the sealing piece is used to close the first through hole and the second through hole, the adhesive layer is transformed into a molten state when heated to open the first through hole and the second through hole, thereby depressurizing the battery, the first connecting portion can be used to connect to a protective plate to improve the connection strength between the outer shell and the protective plate, and the first connecting portion and the second connecting portion are integrally formed, which is beneficial to reducing the battery process and thereby reducing the cost of the battery.

[0062] The specific implementation of the battery provided in the embodiments of the present application is described in detail below with reference to the accompanying drawings.

[0063] Reference Figures 1 to 8 As shown, the battery provided in the present application includes a shell 100, a pressure relief assembly 200 and a battery cell 300, the shell 100 includes a first side wall 110, the first side wall 110 has a first through hole 111, and the first through hole 111 passes through two opposite sides of the first side wall 110 so that the first through hole 111 is connected to the inner and outer sides of the shell 100.

[0064] The pressure relief assembly 200 includes a connecting piece 210, an adhesive layer 230 and a sealing piece 220. The adhesive layer 230 is welded to the first side wall 110. The connecting piece 210 includes a second connecting portion 212 and a first connecting portion 211 connected in sequence along a second direction. The second connecting portion 212 has a second through hole 2121. The projection of the second through hole 2121 on the first side wall 110 at least partially overlaps with the first through hole 111. The first connecting portion 211 is configured to be connected to the protective plate. The adhesive layer 230 is located between the connecting piece 210 and the sealing piece 220. The sealing piece 220 is bonded to the second connecting portion 212 through the adhesive layer 230 to seal the first through hole 111 and the second through hole 2121.

[0065] The first direction is perpendicular to the second direction, and the first direction and the second direction are perpendicular to the third direction at the same time. The third direction is along the thickness direction of the battery cell 300. The first direction can refer to Figure 1 The X direction in the second direction can refer to Figure 1 The Y direction in the third direction can refer to Figure 1 The Z direction in .

[0066] In the present application, the first through hole 111 can serve as both a liquid injection hole and a pressure relief hole. That is, during liquid injection, electrolyte can be injected into the shell 100 through the first through hole 111. When the internal pressure of the battery is high, gas can be released through the first through hole 111, thereby releasing the pressure of the battery.

[0067] After the injection is completed, the first through hole 111 needs to be blocked, so the pressure relief assembly 200 may include a connecting piece 210, a sealing piece 220 and an adhesive layer 230, the connecting piece 210 is connected to the first side wall 110 of the housing 100, and the connecting piece 210 may include a second connecting portion 212, the second connecting portion 212 may improve the connection strength between the adhesive layer 230 and the first side wall 110, so as to avoid insufficient bonding force caused by direct bonding to the first side wall 110, and the second connecting portion 212 has a second through hole 2121 connected to the first through hole 111, so that the inside of the housing 100, the first through hole 111, the second through hole 2121 and the outside of the housing 100 are connected in sequence, so as to form a channel for releasing the gas inside the battery. The sealing piece 220 may be bonded to the second connecting portion 212 through the adhesive layer 230, so as to block the first through hole 111 and the second through hole 2121 to prevent leakage of the electrolyte.

[0068] Among them, the side of the first connecting part 211 facing the adhesive layer 230 can be plated with a nickel layer, or the connecting sheet 210 can be made of a nickel-containing stainless steel sheet to improve the bonding force between the first connecting part 211 and the adhesive layer 230. In addition, the nickel layer can also isolate the first connecting part 211 from contact with external electronic components, thereby preventing the first connecting part 211 from connecting with external electronic components and causing the risk of short circuit.

[0069] It is understandable that when the temperature of the battery increases, the pressure inside the battery will also increase. Therefore, some gas needs to be released to reduce the pressure inside the battery. When the temperature of the battery of the embodiment of the present application reaches a preset temperature, the adhesive layer 230 will change from a solid state to a molten state. At this time, the sealing sheet 220 and the second connecting portion 212 can be separated from each other, thereby allowing the sealing sheet 220 to open the second through hole 2121 and the first through hole 111.

[0070] During the development stage, the battery needs to undergo a drop test and a hot box test. The drop test is used to test the battery's ability to resist accidental impacts, and the hot box test is used to test the battery's reliability in a high temperature environment. Since the sealing sheet 220 is bonded to the connecting sheet 210 through the adhesive layer 230, when the battery falls, the adhesive layer 230 will not crack, and when the battery is at a high temperature, the adhesive layer 230 will melt due to the heat. In this way, the pass rate of the battery in the drop test and the hot box test can be improved.

[0071] The connecting piece 210 may also include a first connecting portion 211, one side of the first connecting portion 211 is connected to the first side wall 110, and the other side is used to connect to the protective plate. The first connecting portion 211 has the function of locally thickening the first side wall 110 to avoid welding through the first side wall 110 when welding the protective plate and the first side wall 110 due to the thin wall thickness of the first side wall 110, thereby reducing the sealing of the outer shell 100.

[0072] Compared with the split setting method in the related art, the first connection part 211 and the second connection part 212 of the present application are integrally formed, which can simplify at least one processing process, thereby effectively reducing the cost of the battery. And compared with the pressure relief method, that is, by setting a thinning area on the shell 100, when the pressure inside the shell 100 exceeds the preset pressure, the thinning area is broken to achieve pressure relief, the battery of the present application adopts a temperature relief method, that is, when the battery temperature reaches the preset temperature, the adhesive layer 230 melts to separate the sealing sheet 220 and the connecting sheet 210, thereby making the first through hole 111 and the second through hole 2121 connect the inner and outer sides of the shell 100. This pressure relief method is more flexible and timely, the explosion-proof performance of the battery is better, and it is easier to implement in terms of process, saving the process cost of the battery, thereby reducing the cost of the battery.

[0073] The battery provided in the embodiment of the present application includes a shell 100 and a pressure relief assembly 200, the shell 100 includes a first side wall 110, the first side wall 110 includes a first through hole 111, the pressure relief assembly 200 includes a connecting sheet 210, an adhesive layer 230 and a sealing sheet 220, the connecting sheet 210 includes a first connecting portion 211 and a second connecting portion 212, the second connecting portion 212 includes a second through hole 2121, the first through hole 111 is provided for electrolyte injection and battery pressure relief, the second connecting portion 212 is provided for connection with the first side wall 110 to improve the connection strength between the adhesive layer 230 and the first side wall 110, and the second through hole 2121 is provided in the second connecting portion 212 to avoid the second connecting portion 212 from being blocked. The first through hole 111 is blocked by the sealing piece 220 and the second connecting part 212, and the adhesive layer 230 is provided to connect the sealing piece 220 and the second connecting part 212, so that the sealing piece 220 blocks the first through hole 111 and the second through hole 2121, and the adhesive layer 230 is melted when the temperature of the battery reaches a preset temperature, so that the sealing piece 220 is separated from the second connecting part 212, so that the first through hole 111 and the second through hole 2121 are exposed for battery pressure relief, and the first connecting part 211 is provided to partially thicken the first side wall 110 to improve the connection strength between the first side wall 110 and the protective plate, and the first connecting part 211 and the second connecting part 212 are integrally formed to simplify the processing procedures of the two, thereby reducing the cost of the battery. Therefore, the battery provided by the embodiment of the present application has low cost and high safety.

[0074] In some embodiments, the thickness of the first connection portion 211 is greater than or equal to the thickness of the second connection portion 212 .

[0075] It can be understood that the first connecting portion 211 is used to locally thicken the first side wall 110 to connect the first side wall 110 and the protective plate. The first connecting portion 211 has a larger thickness, which is conducive to thickening the first side wall 110 to facilitate connection with the protective plate, while the second connecting portion 212 is used to connect the first side wall 110 with the adhesive layer 230, and the second connecting portion 212 also needs to consider the sealing of the first through hole 111. Therefore, the thickness of the second connecting portion 212 is smaller, which can improve the welding yield to ensure the sealing of the first through hole 111 after the second connecting portion 212 is welded to the first side wall 110, thereby preventing the electrolyte from leaking from the gap between the second connecting portion 212 and the first side wall 110.

[0076] In a possible implementation, the thickness of the first connection portion 211 is greater than or equal to the thickness of the first side wall 110 , and the thickness of the second connection portion 212 is less than the thickness of the first side wall 110 .

[0077] With such configuration, the local thickness of the first side wall 110 can be effectively increased through the second connection portion 212 , and the welding yield between the second connection portion 212 and the first side wall 110 can be improved, thereby improving the sealing of the first through hole 111 to prevent electrolyte leakage.

[0078] In some embodiments, the ratio of the thickness of the first connection portion 211 to the thickness of the first sidewall 110 is greater than or equal to 1 and less than or equal to 1.5. And / or, the ratio of the thickness of the second connection portion 212 to the thickness of the first sidewall 110 is greater than or equal to 0.3 and less than or equal to 0.9.

[0079] It should be noted that, since the first connection portion 211 needs to locally thicken the first side wall 110, if the thickness of the first connection portion 211 is less than that of the first side wall 110, the thickening effect of the first connection portion 211 is not obvious, and the connection strength between the first side wall 110 and the protective plate cannot be effectively improved. Since the thickness of the second connection portion 212 is smaller than that of the first side wall 110, if the thickness of the first connection portion 211 exceeds that of the first side wall 110 by too much, it will cause a large thickness gradient between the first connection portion 211 and the second connection portion 212, and excessive thickness of the first connection portion 211 will also increase the ineffective volume of the battery, thereby reducing the energy density of the battery. Therefore, setting the ratio of the thickness of the first connection portion 211 to the thickness of the first side wall 110 between 1 and 1.5 can not only make the first connection portion 211 effectively enhance the local thickness of the first side wall 110, but also prevent the thickness of the first connection portion 211 and the thickness of the second connection portion 212 from being too different.

[0080] Although the thickness of the second connection part 212 is smaller than the thickness of the first side wall 110, which is beneficial to improving the welding yield of the second connection part 212, if the thickness of the second connection part 212 is less than 0.3 times the thickness of the first side wall 110, the strength of the second connection part 212 will be reduced. Therefore, the ratio of the thickness of the second connection part 212 to the thickness of the first side wall 110 is greater than or equal to 0.3 and less than or equal to 0.9, so that the thickness of the second connection part 212 does not exceed the thickness of the first side wall 110, and further after the second connection part 212 is welded to the first side wall 110, the sealing of the first through hole 111 is better.

[0081] For example, the ratio of the thickness of the first connection portion 211 to the thickness of the first side wall 110 is any one of 1, 1.1, 1.2, and 1.5, or is within any two numerical ranges. And / or, the ratio of the thickness of the second connection portion 212 to the thickness of the first side wall 110 is any one of 0.3, 0.5, 0.6, and 0.9, or is within any two numerical ranges.

[0082] In one possible implementation, the battery includes a protective plate located on the first side wall 110, and the protective plate includes a first pin, which is connected to the first connecting portion 211, so that the current flows in sequence between the battery cell 300, the first side wall 110, the first connecting portion 211, the first pin and the protective plate, so that the protective plate regulates the current to protect the battery cell 300.

[0083] In a possible implementation, a portion where the connecting piece 210 and the first side wall 110 overlap each other has a welding area, and the welding area includes a welding mark.

[0084] The weld mark includes at least one of a first weld mark, a second weld mark and a third weld mark. The projection of the first weld mark on the first side wall 110 is arranged around the first through hole 111. The projection shape of the second weld mark on the first side wall 110 is a point shape or a line shape. The projection shape of the third weld mark on the first side wall 110 is a point shape or a line shape.

[0085] It can be understood that the first connection portion 211 is used to connect the first side wall 110 and the first pin, that is, the first connection portion 211 is welded to the first side wall 110 and the first connection portion 211 is also welded to the first pin. Therefore, the welding area has a dot-shaped or line-shaped second weld mark for connecting the first connection portion 211 and the first side wall 110, and the welding area has a dot-shaped or line-shaped third weld mark for connecting the first connection portion 211 and the first pin, and the second connection portion 212 is welded to the first side wall 110, and the second connection portion 212 is bonded to the adhesive layer 230. In order to seal the first through hole 111, the first weld mark for connecting the second connection portion 212 and the first side wall 110 should be connected end to end to form a closed shape. The shape of the first weld mark can match the shape of the first through hole 111 to be arranged around the periphery of the first through hole 111, thereby preventing the electrolyte from leaking along the gap between the first through hole 111, the second connection portion 212 and the first side wall 110.

[0086] In a possible implementation, along the second direction, the distance between the first weld mark and the third weld mark is greater than the distance between the second weld mark and the third weld mark. That is, the first weld mark, the second weld mark and the third weld mark can be arranged in sequence along the second direction to avoid any two of the first weld mark, the second weld mark and the third weld mark from overlapping, so as to avoid forming a higher welding protrusion.

[0087] In some embodiments, a gap is left between the projection of the second weld mark in the third direction and the projection of the third weld mark in the third direction, and / or a gap is left between the projection of the first weld mark in the third direction and the projection of the third weld mark in the third direction. In this way, the first weld mark, the second weld mark and the third weld mark can be arranged in sequence along the second direction.

[0088] In a possible implementation, the first weld mark passes through two opposite sides of the second connection portion 212, and at least a portion of the first weld mark is located on the first side wall 110, and the difference between the outer diameter of the first weld mark and the inner diameter of the first weld mark is greater than or equal to 0.05 mm. And / or, the ratio of the extension dimension of the first weld mark located on the first side wall 110 along the first direction to the thickness of the first side wall 110 is greater than or equal to 0.01.

[0089] That is to say, when laser welding is used for the second connection part 212 and the first side wall 110, the laser beam is irradiated on the second connection part 212 to melt the metal of the second connection part 212 and the first side wall 110, and then a first weld mark is formed after solidification to connect the second connection part 212 and the first side wall 110. The first weld mark not only penetrates the second connection part 212, but is also partially located on the first side wall 110. The melting depth of the first weld mark on the first side wall 110 can exceed 1% of the thickness of the first side wall 110, and the melting width of the first weld mark can be greater than or equal to 0.05 mm, thereby effectively connecting the first side wall 110 and the second connection part 212, thereby improving the sealing of the first weld mark to the first through hole 111.

[0090] Exemplarily, the penetration of the first weld mark on the first side wall 110 can be any one of 1%, 2%, 5%, 10%, and 15% of the thickness of the first side wall 110 or be within any two numerical ranges, and / or the weld width of the first weld mark can be any one of 0.05 mm, 0.07 mm, 0.12 mm, and 0.14 mm or be within any two numerical ranges.

[0091] In one possible implementation, the third weld mark passes through two opposite sides of the first connecting portion 211, at least part of the third weld mark is located on the first side wall 110, and the ratio of the extension dimension of the third weld mark located on the first side wall 110 along the first direction to the thickness of the first side wall 110 is less than or equal to 0.5.

[0092] It should be noted that the third weld mark is used to connect the first pin and the first connecting portion 211. Therefore, the third weld mark may not penetrate the first connecting portion 211, or, when the third weld mark penetrates the two opposite sides of the first connecting portion 211 and is located on the first side wall 110, the penetration of the third weld mark on the first side wall 110 does not exceed 0.5 of the thickness of the first side wall 110 to avoid excessive dispersion of welding heat and reduce the welding yield.

[0093] For example, the ratio of the extension dimension of the third weld mark located on the first side wall 110 along the first direction to the thickness of the first side wall 110 may be any one of 0.1, 0.2, 0.4, and 0.5, or may be within any two value ranges.

[0094] In some embodiments, the first through hole 111 is a round hole and the second through hole 2121 is a waist-shaped hole, which makes it easier to inject electrolyte through the first through hole 111 and reduces the difficulty of adjusting the relative positions of the first through hole 111 and the second through hole 2121.

[0095] In a possible implementation, the length of the second through hole 2121 is greater than the diameter of the first through hole 111, and the width of the second through hole 2121 is less than or equal to twice the diameter of the first through hole 111. In this way, after the connecting sheet 210 is connected to the first side wall 110, it can be ensured that the first through hole 111 and the second through hole 2121 are at least partially connected, so that after the sealing sheet 220 is separated from the connecting sheet 210, the gas can be released from the first through hole 111 and the second through hole 2121.

[0096] In a possible implementation, the shapes of the adhesive layer 230 and the sealing sheet 220 match each other, and the projection of the sealing sheet 220 on the connecting sheet 210 covers the second through hole 2121 .

[0097] It can be understood that the shapes of the adhesive layer 230, the sealing sheet 220 and the second through hole 2121 match each other. When the second through hole 2121 is a waist-shaped hole, the adhesive layer 230 and the sealing sheet 220 are flat, and the projections of the sealing sheet 220 and the adhesive layer 230 on the second connecting portion 212 both cover the second through hole 2121 to completely seal the second through hole 2121, thereby preventing the electrolyte from leaking from the gap between the first connecting portion 211 and the adhesive layer 230, or preventing the electrolyte from leaking from the gap between the adhesive layer 230 and the sealing sheet 220.

[0098] In one possible implementation, the difference between the extension dimension of the adhesive layer 230 along the second direction and the extension dimension of the second through hole 2121 along the second direction is greater than or equal to 0.05 mm, and / or the difference between the extension dimension of the adhesive layer 230 along the third direction and the extension dimension of the second through hole 2121 along the third direction is greater than or equal to 0.05 mm.

[0099] With such configuration, the projection of the adhesive layer 230 on the connecting sheet 210 can completely cover the second through hole 2121 , thereby improving the sealing performance of the first through hole 111 and the second through hole 2121 .

[0100] Exemplarily, the difference between the extension dimension of the adhesive layer 230 along the second direction and the extension dimension of the second through hole 2121 along the second direction can be any one of 0.05㎜, 0.08㎜, 0.1㎜, 0.15㎜ or within any two numerical ranges, and / or, the extension dimension of the adhesive layer 230 along the third direction and the extension dimension of the second through hole 2121 along the third direction can be any one of 0.05㎜, 0.09㎜, 0.1㎜, 0.2㎜ or within any two numerical ranges.

[0101] Reference Figure 2 As shown, in some embodiments, the adhesive layer 230 has a third through hole 231 , the first through hole 111 , the second through hole 2121 and the third through hole 231 are sequentially connected, and the shape of the third through hole 231 matches that of the second through hole 2121 .

[0102] In this way, when the pressure inside the battery is relatively high, the sealing sheet 220 can be opened by pressure to separate the sealing sheet 220 from the adhesive layer 230, or the first notch groove 221 can be broken through by gas, so that the first through hole 111, the second through hole 2121 and the third through hole 231 are connected in sequence between the inner and outer sides of the outer shell 100, thereby relieving the pressure of the battery.

[0103] Reference Figure 2 and Fig. 9 As shown, in a possible implementation, the sealing sheet 220 has a first notch groove 221, the first notch groove 221 extends along a straight line, and the first notch groove 221 can extend along the second direction, and the ratio of the thickness depth of the bottom wall of the first notch groove 221 to the thickness of the sealing sheet 220 is greater than or equal to 0.1 and less than or equal to 0.5. And / or, the width of the first notch groove 221 is greater than or equal to 0.05 mm and less than or equal to 0.5 mm.

[0104] Thus, by locally thinning the sealing sheet 220 to form the first notch groove 221 , when the pressure inside the battery reaches a preset pressure, the gas breaks through the first notch groove 221 to connect the inner and outer sides of the shell 100 , thereby releasing the pressure inside the shell 100 .

[0105] In the specific setting, first, the thickness of the bottom wall of the first notch groove 221 should not be too thin, so as to avoid the bottom wall of the first notch groove 221 being destroyed when the internal pressure of the battery has not reached the preset pressure, causing premature pressure relief, and the thickness of the first notch groove 221 should not be too thick, so as to avoid the pressure in the housing 100 has exceeded the preset pressure, but the first notch groove 221 has not been destroyed, resulting in untimely pressure relief, which may cause problems such as battery fire and explosion. Therefore, setting the ratio of the thickness depth of the bottom wall of the first notch groove 221 to the thickness of the sealing sheet 220 between 0.1 and 0.5 is a relatively reasonable range, which can avoid premature pressure relief of the battery and delayed pressure relief of the battery.

[0106] Secondly, since the first score groove 221 is linear, in order to form a sufficiently large opening to release pressure, the width of the first score groove 221 should be greater than or equal to 0.05 mm, but the first score groove 221 should not be too wide, so as not to excessively reduce the structural strength of the sealing sheet 220. The width of the first score groove 221 should be less than or equal to 0.5 mm.

[0107] For example, the ratio of the thickness depth of the bottom wall of the first notch groove 221 to the thickness of the sealing sheet 220 can be any one of 0.1, 0.3, 0.4, and 0.5, or within any two numerical ranges. And / or, the width of the first notch groove 221 can be any one of 0.05 mm, 0.1 mm, 0.2 mm, and 0.5 mm, or within any two numerical ranges.

[0108] In one possible implementation, the melting point of the adhesive layer 230 is greater than or equal to 80°C and less than or equal to 180°C. In this way, the adhesive layer 230 is conducive to melting when the temperature inside or outside the battery is too high, further enhancing the timeliness of pressure relief. Among them, the adhesive layer 230 can be formed of a single material or a composite of multiple materials. For example, the melting point of the adhesive layer 230 can be any one of 80°C, 100°C, 120°C, 160°C, and 180°C, or within any two numerical ranges.

[0109] Reference Figures 1 to 3 , Fig.10 As shown, in some embodiments, the battery of the present application also includes a battery cell 300 and a pole 400, the battery cell 300 is arranged in the outer shell 100, the battery cell 300 has a first pole ear and a second pole ear with opposite polarities, the first side wall 110 has a fourth through hole 112, the pole 400 is inserted into the outer shell 100 through the fourth through hole 112 to be connected to the first pole ear, the second pole ear is connected to the outer shell 100, and the projection of the second pole ear on the first side wall 110 and the projection of the first connecting portion 211 on the first side wall 110 at least partially overlap, so that the first side wall 110 and the protective plate are connected to the opposite sides of the first connecting portion 211, so that the second pole ear is connected to the protective plate through the first side wall 110 and the first connecting portion 211.

[0110] Thus, the pole 400 can lead the current of the first pole ear to the protection board, and the housing 100 can lead the current of the second pole ear and then lead it to the protection board through the connecting piece 210.

[0111] The housing 100 may be made of metal material, such as an aluminum housing or a steel housing.

[0112] Reference Figure 2 As shown, in a possible implementation, the housing 100 further includes a second side wall 120, the second side wall 120 has a second notch groove 121, the second notch groove 121 extends along an arc, and the ratio of the thickness of the bottom wall of the second notch groove 121 to the thickness of the second side wall 120 is greater than or equal to 0.1 and less than or equal to 0.5. And / or, the width of the second notch groove 121 is greater than or equal to 0.05 mm and less than or equal to 0.5 mm.

[0113] In this way, on the basis of providing the pressure relief assembly 200, the second notch groove 121 is further provided to partially thin the housing 100, so that the battery can take into account two pressure relief methods, thereby improving the safety of the battery.

[0114] In the specific setting, if the ratio of the thickness of the bottom wall of the second notched groove 121 to the thickness of the second side wall 120 is less than 0.1, the thickness of the bottom wall of the second notched groove 121 will be too thin, which will easily cause the second notched groove 121 to be damaged in advance and cause the battery to release pressure in advance. If the ratio of the thickness of the bottom wall of the second notched groove 121 to the thickness of the second side wall 120 is greater than 0.5, the thickness of the second notched groove 121 will be too thick, which will cause the second notched groove 121 to be damaged in time, causing delayed pressure release of the battery. Therefore, setting the ratio of the thickness depth of the bottom wall of the second notched groove 121 to the thickness of the sealing sheet 220 to between 0.1 and 0.5 is a relatively reasonable range, which can prevent both premature and delayed pressure release of the battery.

[0115] If the width of the second notch groove 121 is less than 0.05 mm, the pressure relief opening area is small, which is not conducive to pressure release. If the width of the second notch groove 121 is greater than 0.5 mm, the structural strength of the sealing sheet 220 will be reduced.

[0116] For example, the ratio of the thickness depth of the bottom wall of the second notch groove 121 to the thickness of the second side wall 120 can be any one of 0.1, 0.2, 0.4, and 0.5, or within any two numerical ranges. And / or, the width of the second notch groove 121 is any one of 0.05 mm, 0.08 mm, 0.4 mm, and 0.5 mm, or within any two numerical ranges.

[0117] In a possible implementation, the first side wall 110 and the second side wall 120 are located on two adjacent sides of the housing 100. The second notch groove 121 is located on a side of the second side wall 120 close to the first side wall 110.

[0118] Since the side of the second side wall 120 close to the first side wall 110 is a part with higher pressure in the housing 100, a first notch groove 221 and a second notch groove 121 are respectively provided on the first side wall 110 and the second side wall 120 for pressure relief, thereby effectively improving the safety performance of the battery.

[0119] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A battery, characterized in that: It includes a battery cell, a housing and a pressure relief assembly, wherein the housing includes a first side wall, the first side wall has a first through hole, and the first through hole penetrates two opposite sides of the first side wall along a first direction; The pressure relief assembly includes a connecting piece, a sealing piece and an adhesive layer, the connecting piece includes a first connecting portion and a second connecting portion connected to each other, the first connecting portion and the second connecting portion extend along a second direction, the second connecting portion has a second through hole, the projection of the second through hole on the first side wall at least partially overlaps with the first through hole, the first connecting portion and the first side wall are welded, the adhesive layer is located between the connecting piece and the sealing piece, the sealing piece is bonded to the second connecting portion through the adhesive layer, and the sealing piece blocks the first through hole and the second through hole.

2. The battery according to claim 1, characterized in that The battery cell is arranged in the housing, and the battery cell has a first pole lug and a second pole lug with opposite polarities; The second pole tab is connected to the first side wall, and a projection of the second pole tab on the first side wall and a projection of the first connecting portion on the first side wall at least partially overlap.

3. The battery according to claim 1 or 2, characterized in that: The battery includes a protection plate located on the first side wall, the protection plate includes a first pin, and the first pin is connected to the first connecting portion.

4. The battery according to claim 3, characterized in that The portion where the connecting piece and the first side wall overlap each other has a welding area, and the welding area includes a welding mark; The weld print includes at least one of a first weld print, a second weld print, and a third weld print, wherein the first weld print connects the first side wall and the second connection portion, the second weld print connects the first side wall and the first connection portion, and the third weld print connects the first connection portion and the first pin.

5. The battery according to claim 4, characterized in that Along the second direction, the distance between the first weld mark and the third weld mark is greater than the distance between the second weld mark and the third weld mark.

6. The battery according to claim 4, characterized in that The projection shape of the first welding mark on the first side wall is a closed ring, and the first welding mark is arranged around the circumference of the first through hole; And / or, the projection shape of the second weld mark on the first side wall is dot-shaped or line-shaped; And / or, the projection shape of the third weld mark on the first side wall is dot-shaped or line-shaped.

7. The battery according to claim 4, characterized in that A gap is left between the projection of the second weld mark on the first side wall and the projection of the third weld mark on the first side wall, and / or, A gap is left between the projection of the first weld mark on the first side wall and the projection of the third weld mark on the first side wall.

8. The battery according to claim 4, characterized in that The first weld mark passes through two opposite sides of the second connecting portion, and at least a portion of the first weld mark is located on the first side wall; and / or, The difference between the outer diameter of the first weld mark and the inner diameter of the first weld mark is greater than or equal to 0.05 mm; And / or, a ratio of an extension dimension of the first weld mark located on the first side wall along the first direction to a thickness of the first side wall is greater than or equal to 0.

01.

9. The battery according to claim 4, characterized in that The third weld mark passes through two opposite sides of the first connecting portion, at least part of the third weld mark is located on the first side wall, and the ratio of the extension dimension of the third weld mark located on the first side wall along the first direction to the thickness of the first side wall is less than or equal to 0.

5.

10. The battery according to claim 1 or 2, characterized in that: The thickness of the first connecting portion is greater than or equal to the thickness of the second connecting portion; and / or, The thickness of the first connecting portion is greater than or equal to the thickness of the first side wall, and / or, The thickness of the second connecting portion is smaller than the thickness of the first side wall.

11. The battery according to claim 1 or 2, characterized in that: A ratio of the thickness of the first connecting portion to the thickness of the first side wall is greater than or equal to 1 and less than or equal to 1.5; And / or, a ratio of a thickness of the second connecting portion to a thickness of the first side wall is greater than or equal to 0.3 and less than or equal to 0.

9.

12. The battery according to claim 1 or 2, characterized in that: A ratio of an extension dimension of the second through hole along the second direction to an extension dimension of the second through hole along the third direction is greater than 1; And / or, a ratio of an extension dimension of the second through hole along the third direction to an extension dimension of the first through hole along the third direction is less than or equal to 2.

13. The battery according to claim 12, characterized in that The projections of the sealing sheet and the adhesive layer on the connecting sheet both cover the second through hole.

14. The battery according to claim 13, characterized in that The difference between the extension dimension of the adhesive layer along the second direction and the extension dimension of the second through hole along the second direction is greater than or equal to 0.05 mm; And / or, a difference between an extension dimension of the adhesive layer along the third direction and an extension dimension of the second through hole along the third direction is greater than or equal to 0.05 mm.

15. The battery according to claim 1 or 2, characterized in that: The adhesive layer has a third through hole, the first through hole, the second through hole and the third through hole are connected in sequence, and the shape of the third through hole matches that of the second through hole.

16. The battery according to claim 1 or 2, characterized in that: The sealing sheet has a first notch groove, and the ratio of the thickness depth of the bottom wall of the first notch groove to the thickness of the sealing sheet is greater than or equal to 0.1 and less than or equal to 0.5; And / or, the width of the first notch groove is greater than or equal to 0.05 mm and less than or equal to 0.5 mm.

17. The battery according to claim 1 or 2, characterized in that: The melting point of the adhesive layer is greater than or equal to 80° C. and less than or equal to 180° C.

18. The battery according to claim 1 or 2, characterized in that: The housing further comprises a second side wall, the second side wall having a second notch groove, and a ratio of a thickness of a bottom wall of the second notch groove to a thickness of the second side wall is greater than or equal to 0.1 and less than or equal to 0.5; And / or, the width of the second scoring groove is greater than or equal to 0.05 mm and less than or equal to 0.5 mm.

19. The battery according to claim 18, characterized in that The first side wall and the second side wall are located on two adjacent sides of the housing, and the second notch groove is located on a side of the second side wall close to the first side wall.

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