Battery and battery module

Abstract

The utility model discloses a battery and a battery module. The battery comprises a battery cell, a first collector plate and a pressure relief part, wherein the first collector plate is arranged on one side of the battery cell, the first collector plate comprises a connecting part and a convex part, the connecting part is connected with the battery cell, the convex part is arranged on the connecting part and protrudes in the direction away from the battery cell, and a buffer cavity is formed in the side, close to the battery cell, of the convex part. The pressure relief part is arranged on one side, far away from the battery cell, of the lug boss. According to the battery and the battery module, the problem of thermal runaway of the battery cell caused by battery cell expansion in the prior art is solved.

Description

Technical Field

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

[0002] Batteries are usually equipped with explosion-proof valves to prevent the battery from exploding when it is abnormally overheated. Specifically, when the battery is abnormally hot, the battery valve opens and the gas generated in the battery can flow out of the battery through the explosion-proof valve, thereby preventing the gas pressure in the battery from being too high and causing the battery to explode.

[0003] In the current battery structure, the collector plate and the explosion-proof valve are set separately, which requires a large space and reduces the energy density of the battery. In addition, during the charging and discharging process of the battery, the battery cell undergoes thermal expansion due to chemical reactions. When the thermal expansion of the battery cell exceeds a certain level, it will cause excessive pressure inside the battery cell, thereby causing thermal runaway of the battery cell, and in severe cases, causing the battery to explode. Utility Model Content

[0004] The main purpose of the present application is to provide a battery and a battery module to at least solve the problem of thermal runaway of the battery cell caused by battery cell expansion in the prior art.

[0005] According to one aspect of the present application, a battery is provided, comprising:

[0006] Battery cells;

[0007] A first current collecting disk, the first current collecting disk is arranged on one side of the battery cell, the first current collecting disk comprises a connecting portion and a protruding portion, the connecting portion is connected to the battery cell, the protruding portion is arranged on the connecting portion and protrudes in a direction away from the battery cell, and a buffer cavity is arranged on a side of the protruding portion close to the battery cell;

[0008] A pressure relief portion is arranged on a side of the protruding portion away from the battery core.

[0009] Further, the pressure relief portion includes a pressure relief sheet, the pressure relief sheet has a first surface close to the battery core and a second surface opposite to the battery core, and a pressure relief groove is provided on the first surface and / or the second surface.

[0010] Furthermore, the pressure relief sheet and the raised portion are integrally formed.

[0011] Furthermore, a sinking platform is provided on the side of the protrusion away from the battery core, a first through hole is opened on the sinking platform, the first through hole is connected to the buffer cavity, the pressure relief sheet is covered and sealed at the opening of the first through hole, and the pressure relief sheet and the sinking platform are welded to form a first weld.

[0012] Further, the weld width w1 of the first weld satisfies the relationship: 0.2 mm ≤ w1 ≤ 2 mm; and / or,

[0013] The maximum penetration depth v1 of the first weld satisfies the relationship: 0.2 mm ≤ v1 ≤ 2 mm.

[0014] Furthermore, along the direction in which the protrusion moves away from the battery core, the projection surface of the pressure relief groove includes at least one of a circular ring, an elliptical ring and a polygon.

[0015] Further, along the direction in which the protrusion is away from the battery core, the thickness H0 of the pressure relief sheet satisfies the relationship: 0.2 mm ≤ H0 ≤ 1.5 mm; and / or,

[0016] Along the direction in which the protrusion is away from the battery core, a difference H2 between a thickness H0 of the pressure relief sheet and a maximum depth H1 of the pressure relief groove satisfies the relationship: 0.01 mm ≤ H2 ≤ 0.5 mm.

[0017] Further, along the direction in which the protrusion is away from the battery core, a difference H2 between the thickness H0 of the pressure relief sheet and the maximum depth H1 of the pressure relief groove and a thickness H3 of the first current collecting plate satisfy the relationship: 0.05≤H2 / H3≤0.4.

[0018] Furthermore, the battery further comprises a pole, the pole is provided with a second through hole, the protrusion is passed through the second through hole, the protrusion and the pole are welded to form a second weld, and the pole is connected to the connecting portion.

[0019] Furthermore, along the direction in which the protrusion is away from the battery core, the maximum height h of the protrusion protruding from the connecting portion and the extension length H4 of the second through hole satisfy the relationship: 0mm≤H4-h≤1mm; and / or,

[0020] The maximum weld width w2 of the second weld satisfies the relationship: 0.2 mm ≤ w2 ≤ 2 mm, and the maximum weld depth v2 of the second weld satisfies the relationship: v2 ≥ 0.2 mm; and / or,

[0021] The raised portion includes an outer peripheral side wall, the pressure relief plate is arranged on a side of the outer peripheral side wall away from the battery core, and the minimum distance L between the inner wall surface of the pressure relief groove and the outer peripheral side wall and the maximum weld width w2 of the second weld satisfy the relationship: L-w2 / 2>1mm.

[0022] Furthermore, the battery also includes an insulating component, and the insulating component is sleeved on the outer circumference of the pole.

[0023] Furthermore, the battery further comprises a protective cover, which is arranged at an opening of the second through hole away from the battery cell, and a plurality of third through holes are formed on the protective cover, and the plurality of third through holes are all connected to the second through hole.

[0024] Furthermore, along the direction in which the protrusion is away from the battery core, the sum S2 of the projected areas S1 of the third through holes and the area S3 of the projected surface of the pressure relief groove satisfy the relationship: S2 ≥ S3 / 2.

[0025] Further, the pressure relief groove comprises a circular annular groove, and the distance H5 between the pressure relief sheet and the protective cover and the diameter D of the circular annular groove satisfy the relationship: H5>D / 5; and / or,

[0026] A distance H6 between a surface of the protrusion away from the battery cell and a surface of the pole away from the battery cell satisfies the relationship: 0.3 mm ≤ H6 ≤ 4 mm.

[0027] Furthermore, the battery further comprises a housing assembly having a mounting cavity, wherein the battery cell and the first current collecting plate are arranged in the mounting cavity.

[0028] Furthermore, the pressure relief portion includes a pressure relief sheet, and a pressure relief groove is formed on the pressure relief sheet;

[0029] The volume V of the installation cavity and the area S3 of the projection surface of the pressure relief groove along the direction in which the protrusion is away from the battery core satisfy the relationship: V / S3<4000mm.

[0030] Further, the housing assembly comprises a shell and an end cover, the end cover is arranged on the shell and forms the mounting cavity with the shell, and the end cover is arranged on a side of the battery cell away from the first current collecting plate;

[0031] The battery further includes a second current collecting plate disposed between the battery cell and the end cover.

[0032] Furthermore, the protrusion includes an outer peripheral side wall and a top wall away from the battery core;

[0033] Wherein, the top wall is arranged vertically to the peripheral side wall; or,

[0034] A rounded corner is arranged between the top wall and the outer peripheral side wall, and a maximum radius R of the rounded corner satisfies the relationship: R≤1 mm.

[0035] Furthermore, the raised portion has a bulge, the bulge is arranged on a side of the raised portion away from the battery core, and the pressure relief portion is arranged on a side of the bulge away from the battery core.

[0036] On the other hand, the present application provides a battery module, which includes the above-mentioned battery.

[0037] Compared with the prior art, in the present application, a protrusion is provided on the first current collecting disk, the protrusion protrudes in a direction away from the battery cell, and a buffer cavity is provided on the side of the protrusion close to the battery cell. When the battery is charging and discharging, a chemical reaction occurs inside the battery cell causing the battery cell to expand, and the buffer cavity can accommodate a certain expansion volume, thereby avoiding the problem that the battery cell is squeezed with the battery casing after thermal expansion, causing the battery cell to cause thermal runaway and explosion. In addition, in the present application, since the electrolyte can enter the buffer cavity, the battery of the present application can accommodate more electrolyte, thereby improving the effective energy density of the battery to a certain extent. At the same time, the pressure relief part is provided on the first current collecting disk, which simplifies the structure of the battery and avoids the need to provide a separate pressure relief component on the battery, thereby further improving the energy density of the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0039] Figure 1 A schematic diagram of the structure of the battery disclosed in this application;

[0040] Figure 2 A schematic diagram of a partial explosion structure of the battery disclosed in this application (without the end cover);

[0041] Figure 3 A cross-sectional view of a structure of a battery disclosed in the present application (excluding a protective cover);

[0042] Figure 4 for Figure 3 Schematic diagram of the enlarged structure of the middle I region;

[0043] Figure 5 A cross-sectional view of another structure of the battery disclosed in the present application (including a protective cover);

[0044] Figure 6 for Figure 5 Schematic diagram of the enlarged structure of the middle II region;

[0045] Figure 7 It is a schematic diagram of the structure of the pole disclosed in this application;

[0046] Figure 8 It is an exploded schematic diagram of a structure of the first current collecting plate disclosed in the present application (the protrusion is welded to the pressure relief plate);

[0047] Fig. 9It is a schematic diagram of another structure of the first current collecting plate disclosed in the present application (the protrusion and the pressure relief plate are integrally arranged);

[0048] Fig.10 It is a schematic diagram of another structure of the first current collecting plate disclosed in the present application (the raised portion has a convex bump);

[0049] Fig.11 A schematic diagram of the structure of the pressure relief groove disclosed in this application;

[0050] Fig.12 This is a schematic diagram of the structure of the protective cover disclosed in this application;

[0051] Fig.13 It is a cross-sectional view of another structure of the first current collecting plate disclosed in the present application (the raised portion and the pressure relief plate are integrally arranged);

[0052] Fig.14 A structural cross-sectional view of the first current collecting plate disclosed in the present application (the raised portion and the pressure relief plate are welded);

[0053] Fig.15 It is a cross-sectional view of another structure of the first collecting plate disclosed in the present application (the raised portion has a convex bump).

[0054] The above drawings include the following reference numerals:

[0055] 10. Battery cell; 20. First current collecting plate; 21. Raised portion; 22. Connecting portion; 23. Bump; 30. Pressure relief portion; 31. Pressure relief sheet; 40. Pole; 50. Insulating assembly; 51. Upper plastic; 52. Lower plastic; 60. Seal; 70. Protective cover; 71. Third through hole; 80. Shell assembly; 81. Shell; 82. End cover; 90. Buffer cavity; 91. First weld; 92. Second weld; 211. Sink; 212. First through hole; 311. Pressure relief groove; 401. Second through hole. DETAILED DESCRIPTION

[0056] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0057] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0058] Unless otherwise specifically stated, the relative arrangement, numerical expressions and numerical values ​​of the parts and steps set forth in these embodiments do not limit the scope of the present application. At the same time, it should be understood that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to the actual proportional relationship. The technology, methods and equipment known to those of ordinary skill in the relevant art may not be discussed in detail, but in appropriate cases, the technology, methods and equipment should be considered as a part of the authorization specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, and therefore, once a certain item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.

[0059] See also Figures 1 to 6 As shown, according to an embodiment of the present application, a battery is provided, including a battery cell 10 , a first current collecting plate 20 and a pressure relief portion 30 .

[0060] The first current collecting disc 20 is arranged on one side of the battery cell 10, and the first current collecting disc 20 includes a connecting portion 22 and a protruding portion 21, wherein the connecting portion 22 is connected to the battery cell 10, and the protruding portion 21 is arranged on the connecting portion 22 and protrudes in a direction away from the battery cell 10, and a buffer cavity 90 is arranged on a side of the protruding portion 21 close to the battery cell 10. The pressure relief portion 30 is arranged on a side of the protruding portion 21 away from the battery cell 10.

[0061] In this embodiment, the first current collecting plate 20 is used to collect current, and the pressure relief part 30 is used to relieve pressure on the battery. That is, when the battery expands abnormally due to heat, in order to avoid the battery explosion, the pressure relief part 30 can be opened in time to discharge the gas inside the battery, thereby avoiding excessive internal pressure of the battery, which may cause the battery to explode.

[0062] Compared with the prior art, in this embodiment, a protrusion 21 is provided on the first current collecting disk 20, and the protrusion 21 protrudes in a direction away from the battery cell 10, and a buffer cavity 90 is provided on the side of the protrusion 21 close to the battery cell 10. When the battery is charging and discharging, a chemical reaction occurs inside the battery cell 10 to cause the battery cell 10 to expand, and the buffer cavity 90 can accommodate a certain expansion volume, thereby avoiding the battery cell 10 from being squeezed with the battery shell after thermal expansion, causing the battery cell 10 to cause thermal runaway and explosion. In addition, in this embodiment, since the electrolyte can enter the buffer cavity 90, the battery of this embodiment can accommodate more electrolyte, thereby improving the effective energy density of the battery to a certain extent. At the same time, the pressure relief portion 30 is provided on the first current collecting disk 20, which simplifies the structure of the battery and avoids the need to provide a separate pressure relief component on the battery, thereby further improving the energy density of the battery.

[0063] Furthermore, the pressure relief portion 30 includes a pressure relief sheet 31 . The pressure relief sheet 31 has a first surface close to the battery core 10 and a second surface opposite to the battery core 10 . A pressure relief groove 311 is formed on the first surface and / or the second surface.

[0064] It should be noted that "a pressure relief groove 311 is provided on the first surface and / or the second surface" refers to one of the three situations: a pressure relief groove 311 is provided on the first surface, a pressure relief groove 311 is provided on the second surface, and a pressure relief groove 311 is provided on both the first surface and the second surface. Specifically, the provision of the pressure relief groove 311 reduces the thickness of a part of the pressure relief sheet 31. When the battery expands too much and the buffer cavity 90 cannot withstand it, the battery cell 10 applies pressure to the pressure relief sheet 31. Since the stress at the pressure relief groove 311 of the pressure relief sheet 31 is relatively large, the pressure relief groove 311 is easily ruptured under the action of pressure, so that the gas inside the battery is discharged from the ruptured part, thereby avoiding the explosion of the battery under high pressure.

[0065] In some embodiments, as shown in the attached Fig. 9 and attached Fig.13 As shown, the pressure relief sheet 31 is integrally formed with the protrusion 21. Specifically, the integrally formed arrangement can improve the sealing between the pressure relief sheet 31 and the protrusion 21, thereby preventing foreign impurities from entering the battery through the gap between the protrusion 21 and the pressure relief sheet 31 to contaminate the battery. At the same time, the integral arrangement makes the connection strength between the pressure relief sheet 31 and the protrusion 21 higher, preventing the pressure relief sheet 31 from falling off the protrusion 21 when subjected to external force.

[0066] In addition, when the pressure relief sheet 31 and the protrusion 21 are integrally formed, the first current collecting plate 20 includes a copper current collecting plate, an aluminum current collecting plate, and a copper-aluminum alloy current collecting plate. Since the copper current collecting plate, the aluminum current collecting plate, and the copper-aluminum alloy current collecting plate are corrosion-resistant, when the electrolyte flows to the pressure relief portion 30, it will not corrode the pressure relief portion 30, that is, the explosion value of the pressure relief portion 30 will not change, thereby improving the stability of the battery.

[0067] In some other embodiments, as shown in the attached Figure 8 and attached Fig.14 As shown, a sink 211 is provided on the side of the protrusion 21 away from the battery core 10, and a first through hole 212 is opened on the sink 211. The first through hole 212 is connected to the buffer cavity 90, and the pressure relief sheet 31 covers and seals the opening of the first through hole 212. The pressure relief sheet 31 and the sink 211 are welded to form a first weld 91.

[0068] Specifically, compared with the integrated arrangement of the pressure relief sheet 31 and the protrusion 21, the present embodiment can effectively reduce the manufacturing cost of the battery to a certain extent while ensuring the connection strength between the pressure relief sheet 31 and the protrusion 21 by welding. It is worth mentioning that when the pressure relief sheet 31 and the protrusion 21 are separately arranged, the pressure relief sheet 31 adopts at least one of the three types of corrosion-resistant copper pressure relief sheet, aluminum pressure relief sheet and copper-aluminum alloy pressure relief sheet, so as to avoid the electrolyte in the battery from corroding the pressure relief sheet 31, resulting in a change in the burst value of the pressure relief sheet 31.

[0069] Furthermore, the maximum weld width w1 of the first weld 91 satisfies the relationship: 0.2mm≤w1≤2mm. When w1 satisfies the above relationship, there is a certain welding strength between the pressure relief plate 31 and the sinker 211, and the value of w1 can be 0.2mm, 0.4mm, 0.6mm, 0.8mm, 1mm, 1.2mm, 1.4mm, 1.6mm, 1.8mm and 2mm. Similarly, the maximum weld depth v1 of the first weld 91 satisfies the relationship: 0.2mm≤v1≤2mm. The value of v1 can be 0.2mm, 0.4mm, 0.6mm, 0.8mm, 1mm, 1.2mm, 1.4mm, 1.6mm, 1.8mm and 2mm. When w1 is less than 0.2mm, the connection strength between the pressure relief plate 31 and the sinker 211 is too low, and the pressure relief plate 31 is easily detached from the sinker 211 under the action of external force. When w1 is greater than 2 mm, the first weld is too large, which will affect the bursting value of the pressure relief plate 31 .

[0070] Furthermore, along the direction in which the protrusion 21 is away from the battery cell 10, the projection surface of the pressure relief groove 311 includes at least one of a circular ring, an elliptical ring, and a polygonal shape. Specifically, the circular ring groove, the elliptical groove, and the polygonal groove are convenient for uniform manufacturing, and the polygonal groove includes a regular quadrilateral groove, a regular pentagonal groove, a regular hexagonal groove, etc. In addition, the projection surface of the pressure relief groove 311 can also be other shapes, such as the attached Fig.11 As shown, the projection surface of the pressure relief groove 311 may be S-shaped.

[0071] In order to enable the pressure relief sheet 31 to release pressure in time, in this embodiment, along the direction in which the protrusion 21 is away from the battery core 10, the thickness H0 of the pressure relief sheet 31 satisfies the relationship: 0.2mm≤H0≤1.5mm. That is, when the thickness H0 of the pressure relief sheet 31 is within the above range, the thickness of the pressure relief sheet 31 is moderate, and when the internal pressure of the battery is too large, the pressure relief sheet 31 can break in time to release pressure on the battery. When H0<0.2mm, the thickness of the pressure relief sheet 31 is too thin, and the pressure relief sheet 31 is easily broken by external force, which reduces the stability of the battery. When H0>1.5mm, the thickness of the pressure relief sheet 31 is too thick, and the strength of the pressure relief sheet 31 is too high, resulting in the failure of the pressure relief sheet 31 to break in time when the battery needs to release pressure. The value of H0 can be 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm and 1.5mm.

[0072] Furthermore, along the direction in which the protrusion 21 is away from the battery core 10, the difference H2 between the thickness H0 of the pressure relief sheet 31 and the maximum depth H1 of the pressure relief groove 311 satisfies the relationship: 0.01mm≤H2≤0.5mm. In the present embodiment, H2 is the distance from the bottom of the pressure relief groove 311 to the other side of the extension direction of the pressure relief groove 311, that is, the thickness of the pressure relief sheet 31 at the pressure relief groove 311. When H2 satisfies the above relationship, the pressure relief sheet 31 at the pressure relief groove 311 has a certain thickness, and the pressure relief sheet 31 at the pressure relief groove 311 will not be broken by slight pressure. When H2 is less than 0.01mm, the thickness of the pressure relief sheet 31 at the pressure relief groove 311 is too thin, and it is easy to be broken by slight external force, making the battery pressure relief unstable. When H2 is greater than 0.5mm, the thickness of the pressure relief sheet 31 at the pressure relief groove 311 is relatively high, which may cause the pressure relief sheet 31 to fail to break in time for pressure relief. The value of H2 can be 0.01mm, 0.05mm, 0.1mm, 0.15mm, 0.2mm, 0.25mm, 0.3mm, 0.35mm, 0.4mm, 0.45mm and 0.5mm.

[0073] Furthermore, along the direction in which the protrusion 21 moves away from the battery cell 10 , the difference H2 between the thickness H0 of the pressure relief sheet 31 and the maximum depth H1 of the pressure relief groove 311 and the thickness H3 of the first current collecting plate 20 satisfy the relationship: 0.05≤H2 / H3≤0.4.

[0074] Specifically, when H2 / H3 is greater than 0.4, the thickness of the pressure relief sheet 31 at the pressure relief groove 311 is slightly different from that of the first current collecting disc 20. When the internal pressure of the battery is high, the pressure relief sheet 31 at the pressure relief groove 311 is too thick and is not easy to break. At the same time, the protrusion 21 on the first current collecting disc 20 is deformed by the battery pressure, which changes the actual burst value of the pressure relief sheet 31. When H2 / H3 is less than 0.05, the thickness of the pressure relief sheet 31 at the pressure relief groove 311 is significantly different from that of the first current collecting disc 20, which ultimately causes the pressure relief sheet 31 to break prematurely before reaching the predetermined burst value, making the safety performance of the battery unstable. When 0.05≤H2 / H3≤0.4, it can prevent the pressure relief sheet 31 at the pressure relief groove 311 from being too thick, which causes the pressure relief sheet 31 to fail to rupture in time when it needs to rupture; it can also prevent the pressure relief sheet 31 at the pressure relief groove 311 from being too thin, which causes the pressure relief sheet 31 to open prematurely when the battery cell 10 does not expand too much. The values ​​of H2 / H3 can be 0.05, 0.1, 0.15, 0.2, 0.25, 0.3, 0.35 and 0.4.

[0075] As attached Figure 2 and attached Figure 7 As shown, the battery further includes a pole 40 , which is provided with a second through hole 401 , in which the protrusion 21 is passed, and the protrusion 21 is welded with the pole 40 to form a second weld 92 , and the pole 40 is connected to the connecting portion 22 .

[0076] Specifically, the first current collecting plate 20 collects the current of the battery cell 10 onto the first current collecting plate 20 , and then the current is transmitted to the external device connected to the pole 40 through the pole 40 to provide current to the electrical device.

[0077] Furthermore, along the direction in which the protrusion 21 is away from the battery cell 10, the maximum height h of the protrusion 21 protruding from the connecting portion 22 and the extension length H4 of the second through hole 401 satisfy the relationship: 0mm≤H4-h≤1mm. When H4 and h satisfy the above relationship, it is easy to install the bus duct, and the pressure relief plate 31 will not be higher than the pole 40, causing wear between the pressure relief plate 31 and the electrical equipment, thereby affecting the burst value of the pressure relief plate 31. At the same time, the pressure relief plate 31 will not be too far away from the surface of the side of the pole 40 away from the battery cell 10, resulting in a reduced space utilization rate of the battery. When H4-h is greater than 1mm, there is a large gap between the pressure relief plate 31 and the surface of the side of the pole 40 away from the battery cell 10, which increases the overall volume of the battery and reduces the space utilization rate of the battery. The value of H4-h can be 0, 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm and 1mm.

[0078] To ensure the welding strength between the pole 40 and the raised portion 21, and the second weld does not affect the strength of the pole 40 or the raised portion 21 too much. In this embodiment, the maximum weld width w2 of the second weld 92 satisfies the relationship: 0.2mm≤w2≤2mm, and the maximum weld depth v2 of the second weld 92 satisfies the relationship: v2≥0.2mm. The value of w2 can be 0.2mm, 0.4mm, 0.6mm, 0.8mm, 1mm, 1.2mm, 1.4mm, 1.6mm, 1.8mm and 2mm. The value of v2 can be 0.2mm, 0.4mm, 0.6mm, 0.8mm, 1mm, 1.2mm, 1.4mm, 1.6mm, 1.8mm and 2mm.

[0079] In addition, in order to ensure the welding strength of the pole 40 and the first current collecting plate 20 and to prevent the second weld 92 from affecting the burst value of the pressure relief sheet 31, the protrusion 21 in this embodiment includes an outer peripheral side wall, and the pressure relief sheet 31 is arranged on the side of the outer peripheral side wall away from the battery cell 10. The minimum distance L between the inner wall surface of the pressure relief groove 311 and the outer peripheral side wall and the maximum weld width w2 of the second weld 92 satisfy the relationship: L-w2 / 2>1mm. That is, if the maximum weld width of the second weld 92 is too large, the second weld 92 can pass through the side wall of the pressure relief groove 311 during welding, and affect the groove bottom of the pressure relief groove 311, thereby affecting the burst value of the pressure relief sheet 31.

[0080] Furthermore, the battery further includes an insulating assembly 50, which is sleeved on the periphery of the pole 40. Specifically, the insulating assembly 50 includes an upper plastic 51 and a lower plastic 52, the upper plastic 51 is sleeved on the periphery of the pole 40, and the lower plastic 52 is sleeved on the periphery of the pole 40 and the first current collecting plate 20.

[0081] As attached Figure 5 , Attachment Figure 6 And attached Fig.12 As shown, the battery further includes a protective cover 70 , which covers the opening of the second through hole 401 away from the battery cell 10 . The protective cover 70 is provided with a plurality of third through holes 71 , which are all connected to the second through hole 401 .

[0082] Specifically, the setting of the protective cover 70 can prevent the outside world from affecting the pressure relief sheet 31, causing the explosion value of the pressure relief sheet 31 to change, thereby causing the safety performance of the battery to be unstable. In addition, the multiple third through holes 71 opened on the protective cover 70 can release the gas in the battery after the pressure relief sheet 31 ruptures. At the same time, the multiple third through holes 71 are evenly arranged on the protective cover 70, so that the structure of the protective cover 70 is relatively stable.

[0083] In addition, when the internal pressure of the battery is too high and the pressure relief sheet 31 at the pressure relief groove 311 is broken, if the sum of the areas S2 of the third through holes 71 is small, the gas inside the battery may not be discharged in time, thereby causing the internal pressure of the battery to be too high and explode. Therefore, in order to avoid the above situation, in this embodiment, along the direction in which the protrusion 21 is away from the battery cell 10, the sum S2 of the projected areas S1 of the third through holes 71 and the area S3 of the projected surface of the pressure relief groove 311 satisfy the relationship: S2 ≥ S3 / 2.

[0084] Further, the pressure relief groove 311 includes an annular groove, and the distance H5 between the pressure relief sheet 31 and the protective cover 70 satisfies the relationship between the diameter D of the annular groove: H5>D / 5. When H5 and D satisfy the above relationship, there is a certain gap between the pressure relief sheet 31 and the protective cover 70. When the pressure relief sheet 31 ruptures, the gas inside the battery can pass through the pressure relief sheet 31, and move in the second through hole 401 between the pressure relief sheet 31 and the protective cover 70, and finally pass through the third through hole 71. If H5 is less than D / 5, the distance H5 between the pressure relief sheet 31 and the protective cover 70 is too small, which may cause the third through hole 71 to be shielded by the pressure relief sheet 31 where the pressure relief groove 311 is not provided, so that when the pressure relief groove 311 ruptures, it is difficult for the gas passing through the pressure relief groove 311 to flow out from the third through hole 71.

[0085] In addition, a distance H6 between a surface of the protrusion 21 away from the battery cell 10 and a surface of the electrode 40 away from the battery cell 10 satisfies the relationship: 0.3 mm ≤ H6 ≤ 4 mm.

[0086] Specifically, when H6 is less than 0.3mm, the distance between the raised portion 21 and the protective cover 70 is too close, and the third through hole 71 on the protective cover 70 may be blocked by the pressure relief sheet 31 where the pressure relief groove 311 is not provided, resulting in the gas being unable to pass through the third through hole 71 after the pressure relief groove 311 ruptures. When H6 is greater than 4mm, the distance between the raised portion 21 and the protective cover 70 is too large, resulting in reduced space utilization and energy density of the battery. The value of H6 can be 0.3mm, 0.5mm, 0.7mm, 0.9mm, 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm and 4mm. The preferred value of H6 can be 1.5mm, 2mm, 2.5mm and 3mm.

[0087] Furthermore, the battery further includes a housing assembly 80, the housing assembly 80 having an installation cavity, the battery cell 10 and the first current collecting plate 20 are arranged in the installation cavity. Specifically, the pole 40 is partially arranged in the installation cavity, and the remaining part passes through the housing assembly 80, and the upper plastic 51 is arranged between the housing assembly 80 and the pole 40 to insulate the pole 40 from the housing assembly 80.

[0088] Furthermore, the volume V of the installation cavity and the area S3 of the projection surface of the pressure relief groove 311 along the direction where the protrusion 21 is away from the battery cell 10 satisfy the relationship: V / S3<4000mm. When V / S3 is greater than 4000mm, the difference between the area S3 of the projection surface of the pressure relief groove 311 along the direction where the protrusion 21 is away from the battery cell 10 and the installation cavity is too large, that is, the area S3 is relatively small relative to the battery. When the battery needs to be depressurized, there is more high-pressure gas inside the battery, and the battery cannot be depressurized in time through the smaller pressure relief groove 311. The value of V / S3 can be 100mm, 500mm, 1000mm, 1500mm, 2000mm, 2500mm, 3000mm, 3500mm and 3900mm.

[0089] In some embodiments, as shown in the attached Figure 1 As shown, the housing assembly 80 includes a housing 81 and an end cover 82, the end cover 82 is covered on the housing 81, and forms a mounting cavity (not shown in the figure) with the housing 81, and the end cover 82 is arranged on the side of the battery cell 10 away from the first current collecting disk 20. The battery also includes a second current collecting disk (not shown in the figure), which is arranged between the battery cell 10 and the end cover 82. In this embodiment, the end cover 82 serves as the negative electrode of the battery, and the pole 40 serves as the positive electrode of the battery.

[0090] In one embodiment, the protrusion 21 includes an outer peripheral side wall and a top wall away from the battery cell 10 ; wherein the top wall is vertically arranged to the outer peripheral side wall.

[0091] Specifically, the top wall of the protrusion 21 is a pressure relief sheet 31. When the pressure relief groove 311 on the pressure relief sheet 31 is a circular groove, and the top wall and the peripheral side wall are arranged vertically, the pressure of the battery received by each part of the circular groove is almost the same. When the pressure is large, each part of the circular groove can be broken almost at the same time, so that the battery has a better pressure relief effect.

[0092] In another embodiment, a chamfered corner (not shown in the figure) is provided between the top wall and the outer peripheral side wall, and the maximum radius R of the chamfered corner satisfies the relationship: R≤1mm.

[0093] Specifically, the rounded corners are arranged to facilitate welding of the protrusion 21 and the pole 40, that is, when the pole 40 is sleeved on the outer periphery of the protrusion 21, there will be no interference between the protrusion 21 and the inner wall of the second through hole 401 of the pole 40 due to a certain angle between the top wall of the protrusion 21 and the outer peripheral side wall. The value of R can be 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm and 1mm.

[0094] In addition, when the pressure relief sheet 31 is a circular sheet and the pressure relief groove 311 is an annular groove, the diameter of the circular sheet is larger than the diameter of the second through hole 401 , and the diameter of the annular groove is smaller than the diameter of the second through hole 401 .

[0095] As attached Fig.10 and attached Fig.15 As shown, the protrusion 21 has a convex bulge 23, which is arranged on the side of the protrusion 21 away from the battery cell 10, and the pressure relief portion 30 is arranged on the side of the convex bulge 23 away from the battery cell 10. Specifically, along the direction in which the protrusion 21 is away from the battery cell 10, the projection surface of the convex bulge 23 is located in the protrusion 21, which means that when the pole 40 is sleeved on the outer periphery of the protrusion 21, the inner wall of the second through hole 401 will not interfere with the pressure relief sheet 31, causing the burst value of the pressure relief sheet 31 to change.

[0096] In addition, the battery further includes a seal 60, which is disposed between the upper plastic 51 and the lower plastic 52 to isolate and seal the pole 40 from the housing assembly 80. The seal 60 includes at least one of polybutylene terephthalate plastic, soluble polytetrafluoroethylene plastic, and polyphenylene sulfide plastic.

[0097] On the other hand, the present application also provides a battery module, which includes the battery in the above embodiment, so the battery module includes all the technical effects of the battery in the above embodiment. Since the technical effects of the battery have been described in detail above, they will not be repeated here.

[0098] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0099] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of this application.

[0100] The above are only preferred embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A battery, characterized in that: include: Battery cell (10); a first current collecting disk (20), the first current collecting disk (20) being arranged on one side of the battery cell (10), the first current collecting disk (20) comprising a connecting portion (22) and a protruding portion (21), the connecting portion (22) being connected to the battery cell (10), the protruding portion (21) being arranged on the connecting portion (22) and protruding in a direction away from the battery cell (10), and a buffer cavity (90) being arranged on a side of the protruding portion (21) close to the battery cell (10); A pressure relief portion (30), the pressure relief portion (30) being arranged on a side of the protruding portion (21) away from the battery core (10).

2. The battery according to claim 1, characterized in that The pressure relief portion (30) comprises a pressure relief sheet (31), wherein the pressure relief sheet (31) has a first surface close to the battery core (10) and a second surface opposite to the battery core (10), and a pressure relief groove (311) is provided on the first surface and / or the second surface.

3. The battery according to claim 2, characterized in that The pressure relief sheet (31) and the raised portion (21) are integrally formed.

4. The battery according to claim 2, characterized in that A sink (211) is provided on a side of the protruding portion (21) away from the battery core (10); a first through hole (212) is provided on the sink (211); the first through hole (212) is connected to the buffer cavity (90); the pressure relief sheet (31) is covered and sealed at the opening of the first through hole (212); the pressure relief sheet (31) and the sink (211) are welded to form a first weld (91).

5. The battery according to claim 4, characterized in that The weld width w1 of the first weld (91) satisfies the relationship: 0.2 mm ≤ w1 ≤ 2 mm; and / or, The maximum penetration depth v1 of the first weld (91) satisfies the relationship: 0.2 mm ≤ v1 ≤ 2 mm.

6. The battery according to claim 2, characterized in that Along the direction in which the protrusion (21) moves away from the battery core (10), the projection surface of the pressure relief groove (311) comprises at least one of a circular ring, an elliptical ring and a polygon.

7. The battery according to claim 2, characterized in that Along the direction in which the protrusion (21) is away from the battery core (10), the thickness H0 of the pressure relief sheet (31) satisfies the relationship: 0.2 mm ≤ H0 ≤ 1.5 mm; and / or, Along the direction in which the protrusion (21) moves away from the battery core (10), a difference H2 between the thickness H0 of the pressure relief sheet (31) and the maximum depth H1 of the pressure relief groove (311) satisfies the relationship: 0.01 mm ≤ H2 ≤ 0.5 mm.

8. The battery according to claim 2, characterized in that Along the direction in which the protrusion (21) moves away from the battery core (10), the difference H2 between the thickness H0 of the pressure relief sheet (31) and the maximum depth H1 of the pressure relief groove (311) and the thickness H3 of the first current collecting plate (20) satisfy the relationship: 0.05≤H2 / H3≤0.

4.

9. The battery according to claim 2, characterized in that The battery further comprises a pole (40), the pole (40) being provided with a second through hole (401), the protrusion (21) being passed through the second through hole (401), the protrusion (21) being welded to the pole (40) to form a second weld (92), and the pole (40) being connected to the connecting portion (22).

10. The battery according to claim 9, characterized in that Along the direction in which the protrusion (21) is away from the battery core (10), the maximum height h of the protrusion (21) protruding from the connecting portion (22) and the extension length H4 of the second through hole (401) satisfy the relationship: 0mm≤H4-h≤1mm; and / or, The maximum weld width w2 of the second weld (92) satisfies the relationship: 0.2 mm ≤ w2 ≤ 2 mm, and the maximum weld depth v2 of the second weld (92) satisfies the relationship: v2 ≥ 0.2 mm; and / or, The raised portion (21) comprises an outer peripheral side wall, the pressure relief sheet (31) is arranged on a side of the outer peripheral side wall away from the battery core (10), and the minimum distance L between the inner wall surface of the pressure relief groove (311) and the outer peripheral side wall is The maximum weld width w2 of the second weld (92) satisfies the relationship: L-w2 / 2>1mm.

11. The battery according to claim 9, characterized in that The battery further comprises an insulating component (50), wherein the insulating component (50) is sleeved on the outer circumference of the pole (40).

12. The battery according to claim 9, characterized in that The battery further comprises a protective cover (70), the protective cover (70) being arranged to cover an opening of the second through hole (401) on a side away from the battery cell (10), the protective cover (70) being provided with a plurality of third through holes (71), and the plurality of third through holes (71) being all connected to the second through hole (401).

13. The battery according to claim 12, characterized in that Along the direction in which the protrusion (21) moves away from the battery core (10), the sum S2 of the projected areas S1 of each of the third through holes (71) and the area S3 of the projected surface of the pressure relief groove (311) satisfy the relationship: S2≥S3 / 2.

14. The battery according to claim 12, characterized in that The pressure relief groove (311) comprises a circular ring-shaped groove, and the distance H5 between the pressure relief plate (31) and the protective cover (70) and the diameter D of the circular ring-shaped groove satisfy the relationship: H5>D / 5; and / or, A distance H6 between a surface of the protrusion (21) away from the battery core (10) and a surface of the pole (40) away from the battery core (10) satisfies the relationship: 0.3 mm ≤ H6 ≤ 4 mm.

15. The battery according to claim 1, characterized in that The battery further comprises a housing assembly (80), wherein the housing assembly (80) has a mounting cavity, and the battery cell (10) and the first current collecting plate (20) are arranged in the mounting cavity.

16. The battery according to claim 15, characterized in that The pressure relief portion (30) comprises a pressure relief sheet (31), and a pressure relief groove (311) is provided on the pressure relief sheet (31); The volume V of the installation cavity and the area S3 of the projection surface of the pressure relief groove (311) along the direction of the protrusion (21) away from the battery core (10) satisfy the relationship: V / S3<4000mm.

17. The battery according to claim 15, characterized in that The housing assembly (80) comprises a housing (81) and an end cover (82), wherein the end cover (82) is disposed on the housing (81) and forms the mounting cavity together with the housing (81), and the end cover (82) is disposed on a side of the battery cell (10) away from the first current collecting plate (20); The battery further comprises a second current collecting plate, wherein the second current collecting plate is arranged between the battery cell (10) and the end cover (82).

18. The battery according to any one of claims 1 to 17, characterized in that The raised portion (21) comprises an outer peripheral side wall and a top wall on a side away from the battery core (10); Wherein, the top wall is arranged vertically to the peripheral side wall; or, A rounded corner is arranged between the top wall and the outer peripheral side wall, and a maximum radius R of the rounded corner satisfies the relationship: R≤1 mm.

19. The battery according to any one of claims 1 to 17, characterized in that The raised portion (21) has a bulge (23), the bulge (23) is arranged on a side of the raised portion (21) away from the battery core (10), and the pressure relief portion (30) is arranged on a side of the bulge (23) away from the battery core (10).

20. A battery module, characterized in that: The battery module comprises the battery according to any one of claims 1 to 19.

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