Battery

Abstract

The battery comprises a shell, a pressure relief assembly and a first sealing piece, the shell comprises a first side wall and a second side wall, the first side wall and the second side wall are located on the two adjacent sides of the shell, the first side wall is provided with a first through hole, the first through hole penetrates through the two opposite faces of the first side wall in the first direction, and the second side wall is provided with a second through hole; the second through hole penetrates through the two opposite faces of the second side wall in the second direction, the first through hole and the second through hole communicate with the inner side and the outer side of the shell, and the first sealing piece is welded to the first side wall to block the first through hole; the pressure relief assembly comprises a second sealing piece and a bonding layer, the bonding layer is located between the second side wall and the second sealing piece, and the second sealing piece is bonded to the second side wall through the bonding layer so as to block the second through hole. The battery disclosed by the utility model is 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] During the operation of the battery, a short circuit may occur, causing thermal runaway. At this time, the battery core inside the battery is heated and emits hot gas. At this time, the battery needs to be depressurized to prevent the battery from exploding. In the related technology, grooves are cut on the outer shell of the battery to form a thinning area. When the battery has thermal runaway and the internal pressure of the battery is too high, the gas inside the battery will break through the thinning area to achieve the effect of depressurization.

[0004] However, when a thinning area is set on the shell, if the groove depth is too small, it cannot rupture and release pressure in time. If the groove depth is too large, it is easy to rupture and fail during a battery drop test. Utility Model Content

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

[0006] The battery provided in the present application includes a shell, a pressure relief assembly and a first sealing sheet, the shell includes a first side wall and a second side wall, the first side wall and the second side wall are located on two adjacent sides of the shell, the first side wall has a first through hole, the first through hole penetrates two opposite sides of the first side wall along a first direction, the second side wall has a second through hole, the second through hole penetrates two opposite sides of the second side wall along a second direction, the first sealing sheet is welded to the first side wall, and the first sealing sheet blocks the first through hole;

[0007] The pressure relief assembly includes a second sealing piece and an adhesive layer. The adhesive layer is located between the second side wall and the second sealing piece. The second sealing piece is bonded to the second side wall through the adhesive layer. The second sealing piece blocks the second through hole.

[0008] In a possible implementation manner, the first sealing sheet is welded or bonded to the first side wall.

[0009] In a possible implementation, the first sealing sheet has a first notch groove, and the ratio of the thickness of the bottom wall of the first notch groove to the thickness of the first side wall is greater than or equal to 0.1 and less than or equal to 0.4;

[0010] and / or, the thickness of the bottom wall of the first notch groove is greater than or equal to 5 μm and less than or equal to 45 mm;

[0011] 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.

[0012] In a possible implementation, the first sealing sheet has at least two first notched grooves, the at least two first notched grooves are spaced apart along the second direction, and an extension direction of the first notched grooves is consistent with an extension direction of the first sealing sheet.

[0013] In a possible implementation manner, the thickness of the first sealing sheet is less than or equal to the thickness of the first side wall.

[0014] In a possible implementation manner, the first side wall has a groove, the first through hole is located on the bottom wall of the groove, and the first sealing sheet is located in the groove.

[0015] In a possible implementation manner, the thickness of the first sealing sheet is less than or equal to the depth of the groove.

[0016] In a possible implementation, the battery provided in the present application also includes a battery cell, which includes a battery cell body and a tab connected to each other, the thickness direction of the battery cell body is consistent with the first direction, the battery cell is arranged in a shell, and the projection of the first sealing sheet on the first side wall and the projection of the battery cell on the first side wall are staggered with each other.

[0017] In a possible implementation, the battery provided in the present application further includes insulating tape, the fixing tape is connected between the battery cell body and the shell, and the projection of the first sealing sheet on the first side wall is staggered with the projection of the fixing tape on the first side wall.

[0018] In a possible implementation, the area of ​​the first through hole is greater than or equal to 0.5 mm. 2 .

[0019] 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.

[0020] In a possible implementation, the shape of the adhesive layer matches the shape of the second through hole, and the difference between the extension dimension of the adhesive layer along the first direction and the extension dimension of the second through hole along the first direction is greater than or equal to 0.05 mm;

[0021] 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.

[0022] In a possible implementation, the second sealing sheet has a second notch groove, and the ratio of the thickness of the bottom wall of the second notch groove to the thickness of the second sealing sheet is greater than or equal to 0.1 and less than or equal to 0.5;

[0023] And / or, the ratio of the thickness of the bottom wall of the second notch groove to the 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 notch groove is greater than or equal to 0.05 mm and less than or equal to 0.5 mm.

[0024] In one possible implementation, the pressure relief assembly also includes a third sealing piece, which is welded to the second side wall, and the third sealing piece has a third through hole, and the projection of the third through hole on the second side wall at least partially overlaps with the second through hole, the adhesive layer is bonded between the third sealing piece and the second sealing piece, and the projection of the second sealing piece on the third sealing piece covers the third through hole.

[0025] In one possible implementation, the second through hole is a circular hole, and / or the third through hole is a waist-shaped hole, the length of the third through hole is greater than the diameter of the second through hole, and / or the width of the third through hole is less than the diameter of the second through hole, wherein the width of the third through hole is along the first direction.

[0026] In a possible implementation, the electrode tab includes a first electrode tab, the first electrode tab and a third sealing sheet are connected to two sides of the second side wall, and a projection of the third sealing sheet on the second side wall at least partially overlaps with a projection of the first electrode tab on the second side wall.

[0027] In a possible implementation, the third sealing sheet includes a connecting portion and a sealing portion that are connected to each other, the thickness of the connecting portion is greater than or equal to the thickness of the sealing portion, and the third through hole is located in the sealing portion.

[0028] In a possible implementation, the thickness of the connecting portion is greater than or equal to the thickness of the second side wall, and the ratio of the thickness of the connecting portion to the thickness of the second side wall is greater than or equal to 1 and less than or equal to 1.5;

[0029] And / or, the thickness of the sealing portion is smaller than the thickness of the second side wall, and the ratio of the thickness of the sealing portion to the thickness of the second side wall is greater than or equal to 0.3 and less than or equal to 0.9.

[0030] In a possible implementation of the device to be connected, the first side wall is square, the first sealing piece is square, the length direction of the first sealing piece is consistent with the width direction of the first side wall, and the first sealing piece is located on a side of the first side wall close to the second side wall.

[0031] In a possible implementation, the first side wall is square, the first sealing piece is triangular, the connection between adjacent sides of the first sealing piece is arc-shaped, the first sealing piece is located at the corner of the first side wall, and the first sealing piece is located on the side of the first side wall close to the second side wall.

[0032] In a possible implementation, the battery cell body has a first chamfer and a second chamfer, the first chamfer is arranged corresponding to the first sealing sheet, and the radius of the first chamfer is greater than the radius of the second chamfer.

[0033] In a possible implementation, the first side wall is L-shaped, the first side wall includes a first side edge, a second side edge, and a third side edge connected end to end, the first side edge and the second side edge are vertically arranged, the first side edge and the third side edge are parallelly arranged, and the second side wall is connected to the first side edge;

[0034] The first sealing piece is L-shaped, the connection between adjacent sides of the first sealing piece is arc-shaped, and the first sealing piece is arranged close to the connection between the second side and the third side.

[0035] In one possible implementation,

[0036] The adhesive layer has a fourth through hole, the second through hole, the third through hole and the fourth through hole are connected in sequence, the projection of the second sealing sheet on the adhesive layer covers the fourth through hole, and the cross-sectional area of ​​the fourth through hole is smaller than that of the third through hole.

[0037] The battery provided in the present application includes a shell, a pressure relief assembly and a first sealing sheet, the shell includes a first side wall and a second side wall, the first side wall includes a first through hole, the second side wall includes a second through hole, and the pressure relief assembly includes a second sealing sheet and an adhesive layer. The first sealing sheet is provided to seal the first through hole to prevent leakage of electrolyte through the first through hole, the first sealing sheet is provided to rupture and release pressure when the pressure inside the battery reaches a preset pressure, the adhesive layer is provided to connect the second sealing sheet and the second side wall so that the second sealing sheet seals the second through hole to prevent leakage of electrolyte through the second through hole, and when the temperature of the battery reaches a preset temperature, the adhesive layer is heated and melted, thereby opening the second through hole for pressure relief, thus, the battery of the present application has a higher safety.

[0038] 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

[0039] 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.

[0040] Figure 1 Schematic diagram of the structure of the battery provided in the embodiment of the present application Figure 1 ;

[0041] Figure 2Schematic diagram of the structure of the battery provided in the embodiment of the present application Figure 2 ;

[0042] Figure 3 Schematic diagram of the structure of the battery provided in the embodiment of the present application Figure 3 ;

[0043] Figure 4 A schematic diagram of the internal structure of a battery provided in an embodiment of the present application;

[0044] Figure 5 A schematic diagram of the structure of a first side wall in a battery provided in an embodiment of the present application;

[0045] Figure 6 A schematic diagram of the structure of the first side wall and the first sealing sheet in the battery provided in an embodiment of the present application;

[0046] Figure 7 Schematic diagram of the structure of the battery provided in the embodiment of the present application Figure 4 ;

[0047] Figure 8 Schematic diagram of the structure of the battery provided in the embodiment of the present application Figure 5 ;

[0048] Fig. 9 for Figure 3 A schematic structural diagram of the first side wall;

[0049] Fig.10 Schematic diagram of the structure of the battery provided in the embodiment of the present application Figure 6 ;

[0050] Fig.11 A schematic diagram of the structure of the second sealing sheet in the battery provided in an embodiment of the present application;

[0051] Fig.12 A schematic diagram of the structure of a pressure relief assembly in a battery provided in an embodiment of the present application;

[0052] Fig.13 This is a schematic diagram of the structure of the third sealing piece in the battery provided in an embodiment of the present application.

[0053] Description of reference numerals:

[0054] 100-housing; 110-first side wall; 111-first through hole; 112-groove; 113-first side edge; 114-second side edge; 115-third side edge; 116-fifth through hole; 120-second side wall; 121-second through hole; 200-pressure relief assembly; 210-second sealing plate; 211-second notched groove; 220-adhesive layer; 221-fourth through hole; 230-third sealing plate; 231-third through hole; 232-connecting part; 233-sealing part; 300-first sealing plate; 310-first notched groove; 400-battery cell; 500-connecting plate; 600-pole. DETAILED DESCRIPTION

[0055] 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.

[0056] 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.

[0057] 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.

[0058] 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.

[0059] 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.

[0060] During the operation of the battery, a short circuit may occur, causing thermal runaway. At this time, the battery core inside the battery is heated and emits hot gas. At this time, the battery needs to be depressurized to prevent the battery from exploding. In the related technology, grooves are cut on the outer shell of the battery to form a thinning area. When the battery has thermal runaway and the internal pressure of the battery is too high, the gas inside the battery will break through the thinning area to achieve the effect of depressurization.

[0061] However, when a thinned area is set on the shell, if the groove depth is too small, it cannot rupture and release pressure in time. When the groove depth is too large, it is easy to rupture and fail during a battery drop test, and there will be safety issues of explosion and failure during use.

[0062] In view of this, an embodiment of the present application provides a battery, which is used to achieve pressure relief when the pressure of the battery reaches a preset pressure value by setting a first through hole and a first sealing sheet on the first side wall, and is used to achieve pressure relief when the temperature of the battery reaches a preset temperature by setting a second through hole, a second sealing sheet and an adhesive layer. In this way, by simultaneously arranging a pressure relief structure and a temperature relief structure on two adjacent sides of the outer shell, the problem existing in the single pressure relief method in the related art is solved.

[0063] 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.

[0064] Reference Figures 1 to 6As shown, the battery provided in the present application includes a shell 100, a pressure relief assembly 200 and a first sealing piece 300, the shell 100 includes a first side wall 110 and a second side wall 120, the first side wall 110 and the second side wall 120 are located on two adjacent sides of the shell 100, the first side wall 110 has a first through hole 111, the first through hole 111 passes through two opposite sides of the first side wall 110 along the first direction, the second side wall 120 has a second through hole 121, the second through hole 121 passes through two opposite sides of the second side wall 120 along the second direction, that is, the first through hole 111 and the second through hole 121 are both connected to the inner and outer sides of the shell 100, and the first sealing piece 300 is connected to the first side wall 110 to seal the first through hole 111.

[0065] Exemplarily, the first sealing sheet 300 may be bonded to the first side wall 110, or the first sealing sheet 300 may be welded to the first side wall 110. The pressure relief assembly 200 includes a second sealing sheet 210 and an adhesive layer 220, wherein the adhesive layer 220 is located between the second side wall 120 and the second sealing sheet 210, and the second sealing sheet 210 is bonded to the second side wall 120 through the adhesive layer 220 to block the second through hole 121.

[0066] The first direction is along the thickness direction of the battery cell 400, the second direction is perpendicular to the first direction, and the third direction is perpendicular to both the first direction and the second direction. Figure 1 The X direction in the second direction can refer to Figure 1 The Y direction, the third direction can refer to Figure 1 Z direction.

[0067] In the present application, both the first through hole 111 and the second through hole 121 can be used for pressure relief, and the second through hole 121 can also serve as an injection hole in the injection stage to inject electrolyte into the outer shell 100 through the second through hole 121. In order to close the first through hole 111, the first sealing sheet 300 is welded on the first side wall 110, and the first sealing sheet 300 is locally thinned to form a first notch groove 310. In this way, when the battery is in normal use, the first through hole 111 is in a closed state. When the battery is used abnormally, for example, when the gas production in the battery causes a high pressure, the first notch groove 310 can be flushed open by the high-pressure gas inside the battery, so that the bottom wall of the first notch groove 310 is ruptured, thereby connecting the inside of the outer shell 100 and the outside of the outer shell 100, thereby releasing the pressure inside the battery, thereby avoiding battery explosion and fire.

[0068] In order to close the second through hole 121, the pressure relief assembly 200 includes a second sealing piece 210 and an adhesive layer 220. The adhesive layer 220 is bonded to the second side wall 120 and the second sealing piece 210. The adhesive layer 220 plays a connecting role, and the second sealing piece 210 plays a blocking role. In this way, the second through hole 121 can be reliably sealed, thereby preventing the electrolyte from leaking from the second through hole 121 when the battery is in normal use. When the battery is in a high temperature state, the pressure inside the battery will also increase. When the temperature of the battery reaches a preset temperature, the adhesive layer 220 will change from a solid state to a molten state, thereby causing the second sealing piece 210 to separate from the second side wall 120 to open the second through hole 121 to release gas, thereby realizing the pressure relief function of the battery.

[0069] When the battery is subjected to a hot box test, the adhesive layer 220 melts, and the gas generated by the heat inside the battery can be discharged through the second through hole 121, thereby helping the battery to pass the hot box test smoothly. 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.

[0070] Compared with the method of directly notching the first side wall 110 in the prior art, when the battery falls, firstly, since the first sealing sheet 300 is welded to the first side wall 110, even if the depth of the first notched groove 310 is large, the impact force generated by the fall will first be transmitted to the first seal and the weld mark of the first side wall 110, and then transmitted to the first notched groove 310. The impact force on the first notched groove 310 is attenuated, thereby avoiding the bottom wall of the first notched groove 310 from rupture and failure. Secondly, since the second sealing sheet 210 is bonded to the second side wall 120 through the adhesive layer 220, when the battery falls, the adhesive layer 220 will not crack, and the second sealing sheet 210 will not separate from the second side wall 120, thereby helping the battery to pass the drop test smoothly.

[0071] In the above arrangement, the battery takes into account both the pressure relief method and the temperature relief method, which solves the problem in the related art that the depth of the groove is difficult to accurately control when the shell 100 is partially thinned, thereby improving the safety of the battery.

[0072] The battery provided in the embodiment of the present application includes a shell 100, a pressure relief assembly 200 and a first sealing sheet 300, the first sealing sheet 300 includes a first notch groove 310, the shell 100 includes a first side wall 110 and a second side wall 120, the first side wall 110 includes a first through hole 111, the second side wall 120 includes a second through hole 121, and the pressure relief assembly 200 includes a second sealing sheet 210 and an adhesive layer 220. A first sealing sheet 300 is provided to seal the first through hole 111 to prevent leakage of electrolyte through the first through hole 111; a first notch groove 310 is provided to rupture and release pressure when the pressure inside the battery reaches a preset pressure; an adhesive layer 220 is provided to connect the second sealing sheet 210 and the second side wall 120 so that the second sealing sheet 210 seals the second through hole 121 to prevent leakage of electrolyte through the second through hole 121; and when the temperature of the battery reaches a preset temperature, the adhesive layer 220 is heated and melted, thereby opening the second through hole 121 to release pressure. Therefore, the battery safety of the embodiment of the present application is higher.

[0073] In some embodiments, the first sealing sheet 300 has a first notch groove 310, and the ratio of the thickness of the bottom wall of the first notch groove 310 to the thickness of the first side wall 110 is greater than or equal to 0.1 and less than or equal to 0.4. And / or, the thickness of the bottom wall of the first notch groove 310 is greater than or equal to 5 μm and less than or equal to 45 mm. And / or, the width of the first notch groove 310 is greater than or equal to 0.05 mm and less than or equal to 0.5 mm.

[0074] It should be understood that, firstly, the thickness of the bottom wall of the first notch groove 310 should not be too thin, that is, the depth of the first notch groove 310 should not be too deep, so as to avoid the bottom wall of the first notch groove 310 being damaged when the internal pressure of the battery has not reached the preset pressure, causing the first notch groove 310 to release pressure in advance, and the thickness of the first notch groove 310 should not be too thick, so as to avoid the first notch groove 310 not being damaged when the pressure in the shell 100 has exceeded the preset pressure, causing the first notch groove 310 to fail to release pressure in time, which may cause problems such as battery fire and explosion.

[0075] Therefore, setting the ratio of the bottom wall thickness of the first notched groove 310 to the thickness of the sealing sheet to between 0.1 and 0.5 is a relatively reasonable range, and / or setting the bottom wall thickness of the first notched groove 310 to between 5 μm and 45 mm is a relatively reasonable range, which can avoid both premature pressure relief of the first notched groove 310 and delayed pressure relief of the first notched groove 310.

[0076] Secondly, since the first score groove 310 is in a straight line or arc shape, in order to form a sufficiently large opening to fully release the pressure, the width of the first score groove 310 should be greater than or equal to 0.05 mm, but the first score groove 310 should not be too wide so as not to reduce the structural strength of the first sealing sheet 300. The width of the first score groove 310 should be less than or equal to 0.5 mm.

[0077] For example, the ratio of the thickness of the bottom wall of the first notch groove 310 to the thickness of the first side wall 110 may be any one of 0.1, 0.2, 0.4, and 0.5, or within any two numerical ranges. And / or, the thickness of the bottom wall of the first notch groove 310 may be any one of 5 μm, 20 μm, 60 μm, 30 mm, and 45 mm, or within any two numerical ranges. And / or, the width of the first notch groove 310 may be any one of 0.05 mm, 0.2 mm, 0.4 mm, and 0.5 mm, or within any two numerical ranges.

[0078] In some embodiments, the first sealing sheet 300 has at least two first notched grooves 310, the at least two first notched grooves 310 are arranged at intervals along the second direction, and the first notched grooves 310 extend along the third direction, that is, the extension direction of the first notched grooves 310 is consistent with the extension direction of the first sealing sheet 300. In this way, the first notched grooves 310 can have a greater length, and when the internal pressure of the battery is high, at least one first notched groove 310 of the first sealing sheet 300 will be broken to release the pressure, thereby improving the timeliness of the pressure release of the battery.

[0079] In order to improve the sealing performance of the first through hole 111 after the first sealing sheet 300 is welded to the first side wall 110, in a possible implementation, the thickness of the first sealing sheet 300 is less than or equal to the thickness of the first side wall 110. In this way, when welding the first sealing sheet 300 and the first side wall 110, the welding yield between the two can be improved, thereby ensuring the sealing performance of the first through hole 111, thereby preventing the electrolyte from leaking from the first through hole 111.

[0080] Reference Figures 8 to 9 As shown, in some embodiments, the first side wall 110 has a groove 112 , the first through hole 111 is located at the bottom wall of the groove 112 , the first sealing sheet 300 is located in the groove 112 , and the shape of the first sealing sheet 300 matches that of the groove 112 .

[0081] It can be understood that if the first side wall 110 is not provided with the groove 112, then after the first sealing sheet 300 is welded to the first side wall 110, the first sealing sheet 300 is higher than the outer surface of the first side wall 110. The first sealing sheet 300 is arranged in the groove 112, so that the surface of the first sealing sheet 300 can be lower than the surface of the first side wall 110, or flush with the surface of the first side wall 110, so that the first side wall 110 has no protrusion, thereby avoiding increasing the ineffective volume of the battery.

[0082] In some embodiments, the thickness of the first sealing sheet 300 is less than or equal to the depth of the groove 112. In this way, the first sealing sheet 300 can be completely located in the groove 112, so that the first sealing sheet 300 does not protrude from the groove 112.

[0083] Reference Figures 1 to 4 , Fig.10 As shown, in a possible implementation, the battery provided in the present application also includes a battery cell 400, which is arranged in the housing 100, and the projection of the first sealing sheet 300 on the first side wall 110 and the projection of the battery cell 400 on the first side wall 110 are staggered with each other, wherein the battery cell 400 may include a battery cell body and a pole ear, and the pole ear is connected to the battery cell body for conducting the current generated by the battery cell body.

[0084] When the battery cell 400 is formed by a stacking process, the battery may further include fixing tape, which is connected between the battery cell body and the outer shell 100. The fixing tape can fix the battery cell body to prevent the pole piece and the diaphragm from loosening. The projection of the first sealing sheet 300 on the first side wall 110 and the projection of the fixing tape on the first side wall 110 are staggered with each other.

[0085] That is to say, the projections of the battery cell 400 and the fixing tape on the first side wall 110 are also staggered with the groove 112, so that the side of the groove 112 facing the inside of the housing 100 can be prevented from interfering with the battery cell 400 and the fixing tape, thereby preventing the energy density of the battery from being reduced. When the battery produces gas and expands, the position where the first sealing sheet 300 is located is the position where the battery is subjected to greater force, and the first notched groove 310 is more likely to be ruptured, thereby discharging gas.

[0086] In a possible implementation, the area of ​​the first through hole 111 is greater than or equal to 0.5 mm. 2 In this way, the first through hole 111 can have a sufficiently large opening area to discharge the gas.

[0087] In some embodiments, the melting point of the adhesive layer 220 is greater than or equal to 80° C. and less than or equal to 180° C. This configuration is conducive to melting of the adhesive layer 220 when the temperature inside or outside the battery is too high, further enhancing the timeliness and effectiveness of pressure relief. The adhesive layer 220 can be formed of a single material or a composite of multiple materials.

[0088] Exemplarily, the melting point of the adhesive layer 220 may be any one of 80° C., 110° C., 130° C., 150° C., and 180° C., or may be within a range of any two values.

[0089] In a possible implementation, the shape of the adhesive layer 220 matches the shape of the second through hole 121, and the difference between the extension dimension of the adhesive layer 220 along the first direction and the extension dimension of the second through hole 121 along the first direction is greater than or equal to 0.05 mm. And / or, the difference between the extension dimension of the adhesive layer 220 along the third direction and the extension dimension of the second through hole 121 along the third direction is greater than or equal to 0.05 mm. The third direction is perpendicular to both the first direction and the second direction.

[0090] That is to say, when the second through hole 121 is a waist-shaped hole, the adhesive layer 220 is a matching waist-shaped sheet, the length direction of the second through hole 121 is along the third direction, the width direction of the second through hole 121 is along the second direction, the depth direction of the second through hole 121 is along the first direction, and the length and width of the adhesive layer 220 are both greater than the length and width of the second through hole 121. With such a configuration, the adhesive layer 220 can effectively cover the second through hole 121.

[0091] For example, the difference between the extension dimension of the adhesive layer 220 along the first direction and the extension dimension of the second through hole 121 along the first direction may be any one of 0.05 mm, 0.08 mm, 0.1 mm, 0.15 mm, 0.2 mm, or within any two numerical ranges. And / or, the difference between the extension dimension of the adhesive layer 220 along the third direction and the extension dimension of the second through hole 121 along the third direction may be any one of 0.05 mm, 0.07 mm, 0.9 mm, 0.12 mm, 0.25 mm, or within any two numerical ranges. Figure 2 and Fig.11 As shown, in a possible implementation, the second sealing sheet 210 has a second notched groove 211, and the ratio of the thickness of the bottom wall of the second notched groove 211 to the thickness of the second sealing sheet 210 is greater than or equal to 0.1 and less than or equal to 0.5. And / or, the ratio of the thickness of the bottom wall of the second notched groove 211 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 notched groove 211 is greater than or equal to 0.05 mm and less than or equal to 0.5 mm.

[0092] Thus, by partially thinning the second sealing sheet 210 to form the second notch groove 211, when the temperature of the battery does not reach the preset temperature but the pressure inside the battery reaches the preset pressure, the gas breaks through the bottom wall of the second notch groove 211 to release the pressure.

[0093] In the specific setting, if the ratio of the thickness of the bottom wall of the second notched groove 211 to the thickness of the second sealing sheet 210 and / or the second side wall 120 is less than 0.1, the thickness of the bottom wall of the second notched groove 211 will be too thin, which will easily cause the second notched groove 211 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 211 to the thickness of the second sealing sheet 210 and / or the second side wall 120 is greater than 0.5, the thickness of the second notched groove 211 will be too thick, which will cause the second notched groove 211 to be damaged in time and cause the battery to release pressure in a delayed manner. If the width of the second notched groove 211 is less than 0.05mm, the pressure relief opening area is small, which is not conducive to releasing pressure. If the width of the second notched groove 211 is greater than 0.5mm, the structural strength of the sealing sheet will be reduced.

[0094] Therefore, it is a reasonable range to set the ratio of the thickness of the bottom wall of the second notch groove 211 to the thickness of the second sealing sheet 210 and / or the second side wall 120 to 0.1 to 0.5, and to set the width of the second notch groove 211 to 0.05 mm to 0.5 mm.

[0095] For example, the ratio of the thickness of the bottom wall of the second notch groove 211 to the thickness of the second sealing sheet 210 may be any one of 0.1, 0.3, 0.4, and 0.5, or be within any two numerical ranges. And / or, the width of the second notch groove 211 may be any one of 0.05 mm, 0.07 mm, 0.3 mm, and 0.5 mm, or be within any two numerical ranges.

[0096] Refer to 1 to Figure 4 , Fig.12 As shown, in a possible implementation, the pressure relief assembly 200 also includes a third sealing piece 230, which is welded to the second side wall 120, and has a third through hole 231. The projection of the third through hole 231 on the second side wall 120 at least partially overlaps with the second through hole 121, and the adhesive layer 220 is bonded between the third sealing piece 230 and the second sealing piece 210, and the projection of the second sealing piece 210 on the third sealing piece 230 covers the third through hole 231.

[0097] Therefore, by arranging the third sealing film 230 between the second side wall 120 and the adhesive layer 220, the connection strength between the adhesive layer 220 and the second side wall 120 can be improved to avoid insufficient bonding force caused by direct bonding to the second side wall 120. When the adhesive layer 220 is heated and melted, the second sealing film 210 falls off from the second side wall 120, thereby connecting the second through hole 121 and the third through hole 231 in sequence, and then connecting the inside of the shell 100 and the outside of the shell 100, thereby discharging gas.

[0098] The side of the third sealing sheet 230 facing the adhesive layer 220 may be plated with a nickel layer, or the third sealing sheet 230 may be made of a stainless steel sheet to improve the bonding force between the third sealing sheet 230 and the adhesive layer 220 .

[0099] In a possible implementation, the second through hole 121 is a round hole, the third through hole 231 is a waist-shaped hole, the length of the third through hole 231 is greater than the diameter of the second through hole 121 , and the width of the third through hole 231 is less than the diameter of the second through hole 121 .

[0100] This makes it easier to inject electrolyte through the second through hole 121, and reduces the difficulty of adjusting the relative positions of the second through hole 121 and the third through hole 231 when welding the third sealing sheet 230. In addition, after the third sealing sheet 230 is welded to the second side wall 120, it can be ensured that the second through hole 121 and the third through hole 231 are at least partially connected, so that after the first sealing sheet 300 falls off, the second through hole 121 and the third through hole 231 are in an open state, thereby exhausting gas.

[0101] In a possible implementation, the electrode tab includes a first electrode tab, and the first electrode tab and a third sealing sheet 230 are connected to two sides of the second side wall 120 , and the projection of the third sealing sheet 230 on the second side wall 120 at least partially overlaps with the projection of the first electrode tab on the second side wall 120 .

[0102] It is understandable that the tab may further include a second tab having a polarity opposite to that of the first tab, one of the first tab and the second tab being a positive pole and the other being a negative pole. The first tab and the second tab are both connected to the battery cell 400, and the third sealing sheet 230 may connect the adhesive layer 220 and the second side wall 120. In addition, the third sealing sheet 230 may also partially thicken the second side wall 120 so that the protection plate and the second side wall 120 can be welded when the battery is assembled into a battery pack.

[0103] In a specific implementation, the third sealing sheet 230 includes a connecting portion 232 and a sealing portion 233 connected to each other, the thickness of the connecting portion 232 is greater than or equal to the thickness of the sealing portion 233 , and the third through hole 231 is located in the sealing portion 233 .

[0104] Such a configuration can effectively increase the local thickness of the second side wall 120 through the connecting portion 232, and is beneficial to improving the welding yield of the sealing portion 233 and the second side wall 120, thereby improving the sealing of the second through hole 121 to prevent electrolyte leakage.

[0105] In some embodiments, the thickness of the connecting portion 232 is greater than or equal to the thickness of the second side wall 120, and the ratio of the thickness of the connecting portion 232 to the thickness of the second side wall 120 is greater than or equal to 1 and less than or equal to 1.5. In this way, the connecting portion 232 can effectively enhance the local thickness of the second side wall 120, while the thickness of the connecting portion 232 and the thickness of the sealing portion 233 will not differ too much.

[0106] And / or, the thickness of the sealing portion 233 is less than the thickness of the second side wall 120, and the ratio of the thickness of the sealing portion 233 to the thickness of the second side wall 120 is greater than or equal to 0.3 and less than or equal to 0.9. In this way, the thickness of the sealing portion 233 does not exceed the thickness of the second side wall 120, and further, after the sealing portion 233 is welded to the second side wall 120, the sealing performance of the second through hole 121 is better.

[0107] Exemplarily, the ratio of the thickness of the connecting portion 232 to the thickness of the second side wall 120 is any one of 1, 1.1, 1.3, and 1.5, or is within any two numerical ranges. And / or, the ratio of the thickness of the sealing portion 233 to the thickness of the second side wall 120 is any one of 0.3, 0.5, 0.7, and 0.9, or is within any two numerical ranges. Figure 2 and Fig.13 As shown, in some embodiments, the third sealing sheet 230 includes a connecting portion 232 and a sealing portion 233 connected to each other, the third through hole 231 is located in the sealing portion 233, and the connecting portion 232 is configured to be connected to the device to be connected. Alternatively, it also includes a connecting sheet 500, which is connected to the second side wall 120 and is configured to be connected to the power supply device.

[0108] In the above arrangement, the sealing portion 233 is used to connect with the adhesive layer 220 , the connecting portion 232 is used to partially thicken the second side wall 120 , or the connecting sheet 500 is used to partially thicken the second side wall 120 to facilitate connection with the device to be connected, thereby improving the sealing of the housing 100 .

[0109] It is understandable that the device to be connected may be a protection plate. When a plurality of batteries are assembled into a battery pack, the third sealing plate 230 or the connecting plate 500 needs to be welded to the protection plate so as to regulate the current of the battery through the protection plate.

[0110] In this embodiment, the structure for locally thickening the second side wall 120 may be provided separately or integrated into the third sealing sheet 230 to reduce the number of processing steps and thus reduce the cost of the battery.

[0111] Reference Figure 1 , Figure 2 and Figure 7 As shown, in some embodiments, the first side wall 110 is square, the first sealing piece 300 is square, the length direction of the first sealing piece 300 is consistent with the width direction of the first side wall 110, and the first sealing piece 300 is located on the side of the first side wall 110 close to the second side wall 120.

[0112] Reference Figure 8 and Fig.10 As shown, in other embodiments, the first side wall 110 is square, the first sealing piece 300 is triangular, the connection between adjacent sides of the first sealing piece 300 is arc-shaped, the first sealing piece 300 is located at the corner of the first side wall 110, and the first sealing piece 300 is located on the side of the first side wall 110 close to the second side wall 120.

[0113] It can be understood that in the above two settings, the side of the first side wall 110 close to the second side wall 120 is the part that is subjected to greater force when the battery produces gas and expands, and the projection of the battery cell 400 on the first side wall 110 and the projection of the first sealing piece 300 on the first side wall 110 can be staggered with each other, thereby avoiding reducing the energy density of the battery due to the setting of the first sealing piece 300.

[0114] In a possible implementation, the battery cell 400 has a first chamfer and a second chamfer, the first chamfer is arranged corresponding to the first sealing sheet 300, the second chamfer is the other three corners away from the first sealing sheet 300, and the radius of the first chamfer is greater than the radius of the second chamfer. In this way, the projection of the battery cell 400 on the first side wall 110 and the projection of the first sealing sheet 300 on the first side wall 110 can be staggered, thereby avoiding the reduction of the energy density of the battery due to the provision of the first sealing sheet 300.

[0115] Reference Figure 3 and Fig. 9 As shown, in a possible implementation, the first side wall 110 is L-shaped, and the first side wall 110 includes a first side edge 113, a second side edge 114 and a third side edge 115 connected end to end, the first side edge 113 and the second side edge 114 are vertically arranged, the first side edge 113 and the third side edge 115 are parallelly arranged, and the second side wall 120 is connected to the first side edge 113.

[0116] The first sealing piece 300 is L-shaped, the connection between adjacent sides of the first sealing piece 300 is arc-shaped, and the first sealing piece 300 is disposed close to the connection between the second side 114 and the third side 115 .

[0117] That is to say, in the above-mentioned arrangement, the battery is an L-shaped special-shaped battery, the first sealing sheet 300 is arranged at a corner near the center of the battery, and the projection of the battery cell 400 on the first side wall 110 and the projection of the first sealing sheet 300 on the first side wall 110 are staggered with each other. When the battery expands, the force at this location is greater, which makes it easier for the first notch to be scratched and cracked, thereby discharging gas.

[0118] Reference Figure 2 As shown, in a possible implementation, the shapes of the adhesive layer 220, the second sealing sheet 210 and the third sealing sheet 230 match. The adhesive layer 220 has a fourth through hole 221, the second through hole 121, the third through hole 231 and the fourth through hole 221 are sequentially connected, and the projection of the second sealing sheet 210 on the adhesive layer 220 covers the fourth through hole 221, so that the second sealing sheet 210 blocks the fourth through hole 221.

[0119] In this way, when the pressure inside the battery is relatively high, the second sealing sheet 210 can be opened by gas to separate the second sealing sheet 210 from the adhesive layer 220, or the second notched groove 211 can be broken by gas, so that the second through hole 121, the third through hole 231 and the fourth through hole 221 are sequentially connected between the inner and outer sides of the housing 100, thereby relieving the pressure of the battery. In order to effectively connect the second sealing sheet 210 and the third sealing sheet 230, the cross-sectional area of ​​the fourth through hole 221 needs to be smaller than the cross-sectional area of ​​the third through hole 231, so as to expand the connection area between the second sealing sheet 210 and the third sealing sheet 230.

[0120] Reference Figures 1 to 3 As shown, in some embodiments, the battery of the present application may also include a pole 600, the battery cell 400 has a first pole ear and a second pole ear with opposite polarities, the second side wall 120 has a fifth through hole 116, and the pole 600 is inserted into the outer shell 100 through the fifth through hole 116 to be connected to the first pole ear, and the second pole ear is connected to the outer shell 100.

[0121] Thus, the pole 600 can lead the current of the first pole ear to the device to be connected, and the housing 100 can lead the current of the second pole ear, and then lead it to the device to be connected through the connecting piece 500 or the connecting portion 232. Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present application, rather than to limit it; although the present application is described in detail with reference to the above embodiments, a person skilled in the art should understand that the technical solutions described in the above embodiments can still be modified, or some or all of the technical features therein can be replaced by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solution deviate from the scope of the technical solution of each embodiment of the present application.

Claims

1. A battery, characterized in that: The invention comprises a shell, a pressure relief assembly and a first sealing piece, wherein the shell comprises a first side wall and a second side wall, wherein the first side wall and the second side wall are located at two adjacent sides of the shell, wherein the first side wall has a first through hole, wherein the first through hole penetrates two opposite sides of the first side wall along a first direction, wherein the second side wall has a second through hole, wherein the second through hole penetrates two opposite sides of the second side wall along a second direction, wherein the first sealing piece is connected to the first side wall, and the first sealing piece blocks the first through hole; The pressure relief assembly includes a second sealing piece and an adhesive layer, wherein the adhesive layer is located between the second side wall and the second sealing piece, the second sealing piece is bonded to the second side wall through the adhesive layer, and the second sealing piece blocks the second through hole.

2. The battery according to claim 1, characterized in that The first sealing sheet is welded or bonded to the first side wall.

3. The battery according to claim 1 or 2, characterized in that: The first sealing sheet has at least one first notch groove, and the ratio of the thickness of the bottom wall of the first notch groove to the thickness of the first side wall is greater than or equal to 0.1 and less than or equal to 0.4; and / or, the thickness of the bottom wall of the first notch groove is greater than or equal to 5 μm and less than or equal to 45 mm; 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.

4. The battery according to claim 3, characterized in that The first sealing sheet has at least two first notched grooves, and the at least two first notched grooves are arranged at intervals along the second direction. The extending direction of the first notched grooves is consistent with the extending direction of the first sealing sheet.

5. The battery according to claim 1 or 2, characterized in that: The thickness of the first sealing sheet is less than or equal to the thickness of the first side wall.

6. The battery according to claim 1 or 2, characterized in that: The first side wall has a groove, the first through hole is located on the bottom wall of the groove, and the first sealing sheet is located in the groove.

7. The battery according to claim 6, characterized in that The thickness of the first sealing sheet is less than or equal to the depth of the groove.

8. The battery according to claim 1 or 2, characterized in that: It also includes a battery core, which is arranged in the shell, and the battery core includes a battery core body and a tab that are connected to each other, and the projection of the first sealing sheet on the first side wall is staggered with the projection of the battery core on the first side wall.

9. The battery according to claim 8, characterized in that It also includes fixing tape, which is connected between the pole ear and the shell, and the projection of the first sealing sheet on the first side wall and the projection of the fixing tape on the first side wall are staggered.

10. The battery according to claim 1 or 2, characterized in that: The area of ​​the first through hole is greater than or equal to 0.5 mm 2 .

11. 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.

12. The battery according to claim 1 or 2, characterized in that: The difference between the extension dimension of the adhesive layer along the first direction and the extension dimension of the second through hole along the first 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.

13. The battery according to claim 3, characterized in that The second sealing sheet has a second notch groove, and the ratio of the thickness of the bottom wall of the second notch groove to the thickness of the second sealing sheet is greater than or equal to 0.1 and less than or equal to 0.5; and / or, a ratio of a thickness of a bottom wall of the second notched 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.

14. The battery according to claim 8, characterized in that The pressure relief assembly also includes a third sealing piece, which is welded to the second side wall. The third sealing piece has a third through hole, and a projection of the third through hole on the second side wall at least partially overlaps with the second through hole. The adhesive layer is bonded between the third sealing piece and the second sealing piece, and a projection of the second sealing piece on the third sealing piece covers the third through hole.

15. The battery according to claim 14, characterized in that The electrode tab includes a first electrode tab. The first electrode tab and the third sealing sheet are connected to two opposite sides of the second side wall. The projection of the third sealing sheet on the second side wall at least partially overlaps with the projection of the first electrode tab on the second side wall.

16. The battery according to claim 15, characterized in that The third sealing sheet includes a connecting portion and a sealing portion which are connected to each other. The thickness of the connecting portion is greater than or equal to the thickness of the sealing portion. The third through hole is located in the sealing portion.

17. The battery according to claim 16, characterized in that The thickness of the connecting portion is greater than or equal to the thickness of the second side wall, and the ratio of the thickness of the connecting portion to the thickness of the second side wall is greater than or equal to 1 and less than or equal to 1.5; And / or, the thickness of the sealing portion is smaller than the thickness of the second side wall, and the ratio of the thickness of the sealing portion to the thickness of the second side wall is greater than or equal to 0.3 and less than or equal to 0.

9.

18. The battery according to claim 8, characterized in that The connection between adjacent sides of the first sealing piece is arc-shaped, the first sealing piece is located at the corner of the first side wall, and the first sealing piece is located on a side of the first side wall close to the second side wall.

19. The battery according to claim 18, characterized in that The battery cell body has a first chamfer and a second chamfer, the first chamfer is arranged corresponding to the first sealing sheet, and the radius of the first chamfer is greater than the radius of the second chamfer.

20. The battery according to claim 1 or 2, characterized in that: The first side wall is L-shaped, the first side wall comprises a first side edge, a second side edge and a third side edge connected end to end, the first side edge and the second side edge are arranged vertically, the first side edge and the third side edge are arranged parallelly, and the second side wall is connected to the first side edge; The first sealing piece is L-shaped, the connection between adjacent sides of the first sealing piece is arc-shaped, and the first sealing piece is arranged close to the connection between the second side and the third side.

21. The battery according to claim 14, characterized in that The adhesive layer has a fourth through hole, the second through hole, the third through hole and the fourth through hole are connected in sequence, the projection of the second sealing sheet on the adhesive layer covers the fourth through hole, and the cross-sectional area of ​​the fourth through hole is smaller than the cross-sectional area of ​​the third through hole.

Images