Battery and electric device

Abstract

This application provides a battery and an electrical device, relating to the field of battery technology. The battery includes a casing, a cell, and a cover plate. The casing has a receiving cavity, and at least one end of the casing has an opening. The cell is placed in the receiving cavity and has a tab at the end facing the opening. The cover plate includes a cover plate body and a connecting portion. The connecting portion is disposed around the edge of the cover plate body and is connected to the casing. A gap exists between the cover plate body on the side facing away from the cell and the end face of the connecting portion facing away from the cell. A tab connecting portion is provided on the cover plate body, protruding from the side of the cover plate body facing away from the cell towards the side facing the cell, and the tab connecting portion is connected to the tab. The tab connecting portion of the cover plate protruding towards the cell in this application can press against and connect with the tab, increasing the fit with the tab and greatly reducing the risk of the cover plate body pulling the tab, thus improving the safety performance of the battery.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, and in particular to a battery and an electrical device. Background Technology

[0002] Cylindrical batteries are widely used in power batteries and energy storage batteries due to their high safety and reliability. To improve space utilization, some existing cylindrical batteries eliminate the negative electrode busbar and instead use laser-welded negative electrode tabs and cover plates. To reduce the difficulty of laser-welding, the thickness of the cover plate is reduced. Furthermore, to prevent the thinned cover plate from directly contacting and being damaged by other external components, a folded edge is added to the edge of the cover plate, with the folded end overlapping the opening of the casing.

[0003] However, the above structure results in a distance between the cover plate and the end of the casing. When the battery is placed on the ground, there is a gap between the cover plate and the ground. During the charging and discharging process of the battery, the gas production will increase the internal gas pressure of the battery, thereby squeezing the cover plate outward. The outward deformation of the cover plate will pull the tabs, reducing the safety performance of the battery. Utility Model Content

[0004] The purpose of this application is to provide a battery and an electrical device to solve the technical problem of poor battery safety in the prior art.

[0005] To achieve the above objectives, the technical solution adopted in this application is as follows:

[0006] In a first aspect, this application provides a battery, comprising: a casing, a battery cell, and a cover plate. The casing has a receiving cavity, and at least one end of the casing has an opening. The battery cell is placed in the receiving cavity, and the battery cell has a tab at the end facing the opening. The cover plate includes a cover plate body and a connecting portion. The connecting portion is disposed around the edge of the cover plate body and is connected to the casing. There is a gap between the cover plate body on the side facing away from the battery cell and the end face of the connecting portion facing away from the battery cell. A tab connecting portion is provided on the cover plate body, and the tab connecting portion protrudes from the side of the cover plate body facing away from the battery cell to the side facing the battery cell. The tab connecting portion is connected to the tab.

[0007] In one or more embodiments of this application, the electrode connection portion includes a plurality of electrode connections, which are arranged circumferentially around the cover plate body.

[0008] In one or more embodiments of this application, along the axial direction of the battery, the connecting portion extends from the edge of the cover plate body in a direction away from the battery cell and is connected to the casing. A protective member is provided in the gap, the outer edge of the protective member is connected to the connecting portion of the cover plate, the inner edge of the protective member extends toward the central axis of the cover plate body, and the protective member covers at least part of the tab connecting portion.

[0009] In one or more embodiments of this application, the length of the protective member covering the electrode tab connection portion along the radial direction of the cover plate body is D, satisfying: 0 < D < 15 mm.

[0010] In one or more embodiments of this application, the protective element is annular.

[0011] In one or more embodiments of this application, the cover plate body is provided with a thinning portion, which is arranged around the circumference of the cover plate body and located near its outer edge. The thickness of the thinning portion is less than the thickness of the unthinned area of ​​the cover plate body. Along the radial direction of the cover plate body, the thinning portion is spaced apart from the electrode tab connection portion, and the protective member covers the thinning portion.

[0012] In one or more embodiments of this application, the surface of the thinned portion facing the battery cell and / or the surface facing away from the battery cell is arc-shaped.

[0013] In one or more embodiments of this application, the protective member has a puncture portion on the side facing the thinned portion, the puncture portion is provided at the point where the thickness of the thinned portion is the smallest, and there is a gap between the puncture portion and the thinned portion.

[0014] In one or more embodiments of this application, a recess is provided at the position of the protective member corresponding to the puncture portion, and the puncture portion is provided in the recess.

[0015] Secondly, this application provides an electrical device including the battery described in any of the first aspects.

[0016] Based on the above technical solution, the battery and power-consuming device of this application have at least the following beneficial technical effects:

[0017] The battery of this application designs the cover plate to include a cover plate body and a connecting part. The connecting part is used to connect with the housing. There is a gap between the cover plate body on the side away from the battery cell and the end face of the connecting part that is away from the battery cell, which can prevent the cover plate body from directly contacting other external parts and causing damage. The cover plate body is provided with a tab connecting part that protrudes from the side away from the battery cell to the side facing the battery cell. The tab connecting part that protrudes towards the battery cell can press against the tab and connect with the tab, increasing the degree of fit with the tab. When gas is generated inside the battery and the internal gas pressure of the battery increases, squeezing the cover plate in the direction of the battery exterior, the risk of the cover plate body pulling the tab can be greatly reduced, thus improving the safety performance of the battery. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the exploded decomposition structure of the battery provided in the embodiment of this application.

[0020] Figure 2 This is a cross-sectional view of the battery provided in an embodiment of this application.

[0021] Figure 3 This is a three-dimensional structural diagram of the cover plate in the battery provided in an embodiment of this application.

[0022] Figure 4 This is a three-dimensional structural diagram of the connection between the cover plate and the protective component in the battery provided in the embodiments of this application.

[0023] Figure 5 This is a three-dimensional structural diagram of the protective component in the battery provided in the embodiments of this application.

[0024] Figure 6 This is a cross-sectional view of the battery casing provided in the embodiments of this application.

[0025] Figure 7 yes Figure 6 Enlarged view of point A in the image.

[0026] In the figure: 10-shell; 11-receiving cavity; 12-opening; 13-electrode terminal; 20-cell; 21-tab; 30-cover plate; 31-tab connection part; 32-thinning part; 33-connection part; 34-cover plate body; 40-protective component; 41-puncture part; 42-recess. Detailed Implementation

[0027] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of this application.

[0028] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to that other component.

[0029] It should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0030] In related technologies, some cylindrical batteries eliminate the busbar structure and instead use laser-welded connections between the battery cover and the tabs to improve space utilization. However, to reduce the difficulty of laser penetration, the cover thickness is reduced. To prevent the thinned cover from directly contacting and being damaged by other external components, a gap is created between the cover and the casing. With this design, when gas is generated during charging and discharging, increasing the internal pressure, the cover is pushed outwards, causing it to pull on the tabs and affecting battery safety.

[0031] Based on the above considerations, in order to solve the technical problem of poor battery safety in existing batteries, this application provides a battery and an electrical device.

[0032] The battery described in this application may also refer to a single battery cell. Batteries may include, but are not limited to, lithium-ion batteries, sodium-ion batteries, sodium-lithium-ion batteries, lithium metal batteries, sodium metal batteries, lithium-sulfur batteries, magnesium-ion batteries, nickel-metal hydride batteries, nickel-cadmium batteries, lead-acid batteries, etc.

[0033] As an example, the battery in this application can be a cylindrical battery, which refers to a battery whose shape is cylindrical or similar to a cylindrical structure.

[0034] The batteries disclosed in this application can be used in electrical devices that use batteries as a power source or in energy storage systems that use batteries as energy storage elements. Electrical devices include, but are not limited to, vehicles, mobile phones, portable devices, laptops, ships, spacecraft, electric toys, power tools, energy storage devices, amusement equipment, elevators, and lifting equipment, etc. Electric toys include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, or electric airplane toys, etc.; power tools include metal cutting power tools, grinding power tools, assembly power tools, and railway power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers, etc.; energy storage devices can be energy storage walls, base station energy storage, container energy storage, etc.; amusement equipment can be carousels, drop towers, etc.

[0035] The technical solution of this application will now be described in detail with reference to the accompanying drawings.

[0036] Please refer to Figure 1 This application provides a battery comprising: a casing 10, a battery cell 20, and a cover plate 30. The casing 10 has a receiving cavity 11, and at least one end of the casing 10 has an opening 12. In some embodiments, the casing 10 has a cylindrical shape to correspond to the shape of the battery cell 20. The battery cell 20, also referred to as an electrode assembly, is composed of a positive electrode, a negative electrode, and a separator. The battery cell 20 is placed within the receiving cavity 11, and has a tab 21 at the end facing the opening 12; the battery cell 20 also has a cylindrical shape, with its axial direction parallel to the axial direction of the casing 10, and its radial direction parallel to the radial direction of the casing 10. The cover plate 30 includes a cover plate body 34 and a connecting portion 33, which is disposed around the edge of the cover plate body 34 and connected to the casing 10, thereby connecting the cover plate 30 to the casing 10. The cover body 34 has a gap between the side facing away from the cell 20 and the end face of the connecting portion 33 facing away from the cell 20. It is understood that, along the axial direction of the housing 10, the gap between the side of the cover body 34 facing the outside of the cell 20 and the end face of the connecting portion 33 facing the outside of the cell 20 is provided so that when the battery is placed axially on a flat surface (e.g., the ground), there is a gap between the cover body 34 and the surface (e.g., the ground) to prevent direct contact and damage between the cover body 34 and other external components. A tab connecting portion 31 is provided on the cover body 34, protruding from the side of the cover body 34 facing away from the cell 20 towards the side facing the cell 20, and the tab connecting portion 31 is connected to the tab 21. It is understandable that the tab connection part 31 is a protruding structure of the cover plate body 34 from the outer surface of the battery toward the inside of the battery. Therefore, the thickness of the tab connection part 31 is the same as the thickness of other areas of the cover plate body 34. It will not increase the thickness of the tab connection part 31, nor will it increase the difficulty of laser penetration welding to fix the tab connection part 31 to the tab.

[0037] In the technical solution of this application embodiment, the cover plate 30 is designed to include a cover plate body 34 and a connecting part 33. The connecting part 33 is used to connect the cover plate body 34 to the housing 10. There is a gap between the side of the cover plate body 34 away from the cell 20 and the end face of the connecting part 33 away from the cell 20, which can prevent the cover plate body 34 from being damaged by direct contact with other external parts. The cover plate body 34 is provided with a tab connecting part 31 that protrudes from the side away from the cell 20 to the side facing the cell 20. The tab connecting part 31 that protrudes towards the cell 20 can press against the tab and connect with the tab, increasing the degree of fit with the tab. When gas is generated inside the battery and the internal gas pressure of the battery increases, the cover plate is squeezed towards the outside of the battery, which can greatly reduce the risk of the cover plate body 34 pulling the tab and improve the safety performance of the battery.

[0038] In some embodiments, the tab 21 of this application can be a negative tab. Of course, in other embodiments, the tab 21 can also be a positive tab. The tab 21 can also be understood as a group of tabs, consisting of multiple tabs arranged circumferentially around the battery cell 20, such as... Figure 1 As shown.

[0039] In some embodiments, along the axial direction of the housing 10, one end of the housing 10 is a closed structure, and the other end is an opening 12, such as... Figure 2 As shown, an electrode terminal 13 is provided at the closed end of the housing 10, and the electrode terminal 13 is insulated from the housing 1. For example, the electrode terminal 13 and the housing 10 are insulated from each other by a plastic part to insulate the positive and negative electrodes and prevent short circuits. When the tab at this end is the positive tab, the electrode terminal 13 is connected to the positive tab, and at this time, the electrode terminal 13 is the positive electrode terminal, serving as the positive output terminal. The open end of the housing 10 is fixed to the open end of the housing 10 by a cover plate 30, and the tab connection part 31 of the cover plate 30 is connected to the negative tab, serving as the negative output of the battery.

[0040] Please refer to Figure 3 The electrode connection portion 31 includes multiple portions, which are arranged circumferentially around the cover plate body 34. Since the electrode 21 extends radially along the cell 20 and includes multiple portions arranged circumferentially along the cell 20, the electrode connection portions 31 also extend radially along the cover plate body 34 and are arranged circumferentially around the cover plate body 34 to increase the connection area between the electrode connection portion 31 and the electrode 21, thereby improving current transmission performance. Simultaneously, since the electrode connection portions 31 protrude from the side of the cover plate body 34 away from the cell 20 towards the cell 20 and are arranged circumferentially around the cover plate body 34, the electrode connection portions 31 can also act as reinforcing ribs for the cover plate body 34, thereby improving the mechanical strength of the cover plate 30 and, to a certain extent, enhancing the cover plate 30's resistance to deformation, thus further reducing the risk of the cover plate being stretched and the electrode 21 being pulled by deformation.

[0041] Please refer to Figure 3 To achieve the connection between the cover plate body 34 and the housing 10, the cover plate 30 is provided with a connecting portion 33. Along the axial direction of the battery, the connecting portion 33 extends from the edge of the cover plate body 34 in a direction away from the cell 20 and connects with the housing 10. It can be understood that the connecting portion 33 is arranged around the circumferential edge of the cover plate body 34, and first extends from the edge of the cover plate body 34 towards the outside of the cell 20, and then extends radially away from the cover plate body 34, so that the connecting portion 33 can overlap the open end face of the housing 10, such as... Figure 7As shown. The cover plate 30 is welded and fixed to the housing 10 at the overlap. In this way, a gap is formed between the side of the cover plate body 34 facing away from the cell 20 and the end face of the connecting part 33 facing away from the cell 20. This prevents the cover plate body 34 from coming into contact with other external parts and being damaged.

[0042] In some embodiments, the connecting portion 33 may be integral with the cover plate body 34. In other embodiments, the connecting portion 33 may be separate from the cover plate body 34.

[0043] Please refer to Figure 4 In some embodiments of this application, a protective element 40 may be provided within the gap, that is, a protective element 40 is provided on the side of the cover plate body 34 facing away from the cell 20, and the surface of the protective element 40 facing away from the cover plate body 34 may be on the same plane as the end face of the connecting portion 33. Therefore, it can be understood that the protective element 40 fills the gap space formed by the end faces of the cover plate body 34 and the connecting portion 33. The outer edge of the protective element 40 is connected to the connecting portion 33 of the cover plate 30, for example, by welding, and the inner edge of the protective element 40 extends toward the central axis of the cover plate body 34, and the protective element 40 covers at least a portion of the electrode tab connecting portion 31. Figure 5 As shown, in some embodiments, the protective member 40 has an annular structure. The outer edge of the protective member 40 can be understood as the outer edge away from the central axis, and the inner edge of the protective member 40 can be understood as the inner edge close to the central axis.

[0044] With this configuration, the protective component 40 can limit the deformation of the cover body 34, reducing the deformation space of the cover body 34. When the cover 30 is deformed by being squeezed outwards from the battery, the protective component 40 contacts the cover body 34, suppressing the deformation of the cover body 34, thereby reducing the risk of the cover body 34 being pulled by the force of deformation. At the same time, the protective component 40 can also prevent the cover body 34 from directly contacting external parts or the ground and being damaged.

[0045] like Figure 6 and Figure 7As shown, in some embodiments, the length of the protective member 40 covering the tab connection portion 31 along the radial direction of the cover plate body 34 is D, satisfying: 0 < D < 15 mm. For example, D can be within multiple ranges such as 0 < D < 10 mm, 0 < D < 8 mm, 0 < D < 5 mm, 2 mm < D < 15 mm, 4 mm < D < 10 mm, 5 < D < 8 mm, etc. Specifically, D can be 1 mm, 2 mm, 4 mm, 5 mm, 7 mm, 8 mm, 9 mm, 12 mm, 13 mm, 15 mm, etc., or any value between any two of the above. By setting the coverage length D within the aforementioned range, the protective component 40 can provide sufficient protection for the cover body 34, preventing it from deforming and pulling on the tabs, without increasing the structural complexity of the battery. When the coverage length D is less than or equal to 0, that is, when the protective component 40 does not cover the tab connection 31, the protective effect of the protective component 40 on the cover body 34 is relatively small. When the coverage length D is greater than or equal to 15mm, it will increase the complexity of the battery structure and defeat the purpose of eliminating the busbar.

[0046] In some embodiments, the protective element 40 and the cover plate body 34 can be connected by spot welding. That is, the protective element 40 and the cover plate body 34 are not completely sealed.

[0047] Please refer to Figure 3 In some embodiments of this application, the cover plate body 34 is further provided with a thinning portion 32. The thinning portion 32 is arranged circumferentially around the cover plate body 34 and located near its outer edge. The thickness of the thinning portion 32 is less than the thickness of the unthinned area of ​​the cover plate body 34. Because the thickness of the thinning portion 32 is less than the thickness of the unthinned area of ​​the cover plate body 34, the thinning portion 32 is relatively weaker than other unthinned areas. When the internal pressure of the battery is too high, the thinning portion 32 is easily torn, releasing internal pressure and acting as an explosion-proof valve to improve battery safety. At the same time, the thinning portion 32 is located near the outer edge of the cover plate body 34, which can prevent it from affecting the electrode connection portion 31.

[0048] like Figure 3 As shown, in some embodiments, the thinned portion 32 is spaced apart from the tab connection portion 31 along the radial direction of the cover plate body 34, in order to avoid the thinned portion 32 affecting the tab connection portion 31.

[0049] Please refer to Figure 4 and Figure 7 In some embodiments, the protective member 40 covers the thinned portion 32. That is, the projection of the thinned portion 32 falls within the projection range of the protective member 40, so that the protective member 40 can protect the thinned portion 32. Since the protective member 40 and the cover plate body 34 are spot-welded together and are not completely sealed, the protective member 40 will not affect the pressure relief through the thinned portion 32.

[0050] like Figure 7 As shown, in some embodiments, the surface of the thinning portion 32 facing the cell 20 and / or the surface facing away from the cell 20 is arc-shaped. It is understood that the thinning portion 32 may be arc-shaped on the surface facing the cell 20, or on the surface facing away from the cell 20, or both surfaces may be arc-shaped. Thus, the thinning portion 32 as a whole is a circular arc or an elliptical arc, such as... Figure 3 As shown. Therefore, the thickness of the thinned portion 32 is uniformly reduced. Compared with the thinned portion formed by the scoring groove, the thickness change area of ​​the scoring groove is abrupt and the consistency is poor. The thinned portion 32 of this application can make it more uniform in stress, with higher consistency, higher mechanical strength, and stronger resistance to deformation of the cover plate body 34.

[0051] To further ensure that the thinned portion 32 can be rapidly destroyed when the internal gas pressure of the battery is high, please refer to... Figure 5 or Figure 7 The protective member 40 has a piercing portion 41 on the side facing the thinned portion 32. In some embodiments, the longitudinal section of the piercing portion 41 can be triangular, with its pointed corners facing the thinned portion 32. The piercing portion 41 is provided at the point where the thickness of the thinned portion 32 is the smallest, and there is a gap between the piercing portion 41 and the thinned portion 32. On the one hand, when gas is generated inside the battery, causing the gas pressure to increase, the thinned portion 32 will move closer to the piercing portion 41, causing the piercing portion 41 to pierce the thinned portion 32, thus helping to tear the thinned portion 32. The piercing portion 41 is provided at the point where the thickness of the thinned portion 32 is the smallest, making it easier for the piercing portion 41 to pierce the thinned portion 32. Under normal operating conditions, there is a gap between the thinned portion 32 and the piercing portion 41, which will not damage the thinned portion 32.

[0052] To further prevent the puncture portion 41 from damaging the thinned portion 32 during normal operation, a recess 42 is provided on the protective member 40 at the position corresponding to the puncture portion 41. This recess 42 is formed by recessing the surface of the protective member 40, and its groove depth is less than the thickness of the protective member 40. The puncture portion 41 is located in the recess 42. This further protects the thinned portion 32 from damage during normal operation.

[0053] In some embodiments, such as Figure 5 As shown, multiple puncture portions 41 can be provided along the circumference of the protective member 40, with the multiple puncture portions 41 arranged at intervals. When the internal gas pressure of the battery is high, only one puncture of the thinning portion 32 is needed to meet the pressure relief requirement. Of course, in some other embodiments, the puncture portion 41 can also be a ring-shaped arrangement surrounding the circumference of the protective member 40.

[0054] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A battery, characterized in that, include: A housing (10) having a receiving cavity (11), wherein at least one end of the housing (10) has an opening (12); A battery cell (20) is placed inside the receiving cavity (11), and the battery cell (20) has a tab (21) at the end facing the opening (12); A cover plate (30) includes a cover plate body (34) and a connecting part (33). The connecting part (33) is arranged around the edge of the cover plate body (34). The connecting part (33) is connected to the housing (10). There is a gap between the cover plate body (34) on the side away from the battery cell (20) and the end face of the connecting part (33) away from the battery cell (20). A tab connecting part (31) is provided on the cover plate body (34). The tab connecting part (31) protrudes from the side of the cover plate body (34) away from the battery cell (20) toward the side facing the battery cell (20). The tab connecting part (31) is connected to the tab (21).

2. The battery according to claim 1, characterized in that, The electrode connecting part (31) includes a plurality of electrode connecting parts (31) arranged circumferentially around the cover plate body (34).

3. The battery according to claim 1, characterized in that, Along the axial direction of the battery, the connecting portion (33) extends from the edge of the cover body (34) away from the cell (20) and is connected to the housing (10). A protective member (40) is provided in the gap. The outer edge of the protective member (40) is connected to the connecting portion (33) of the cover (30). The inner edge of the protective member (40) extends toward the central axis of the cover body (34), and the protective member (40) covers at least part of the tab connecting portion (31).

4. The battery according to claim 3, characterized in that, Along the radial direction of the cover plate body (34), the length of the protective member (40) covering the electrode connecting part (31) is D, which satisfies: 0 < D < 15 mm.

5. The battery according to claim 3, characterized in that, The protective element (40) is in the shape of a ring.

6. The battery according to any one of claims 1 to 5, characterized in that, The cover plate body (34) is provided with a thinning portion (32). The thinning portion (32) is arranged around the circumference of the cover plate body (34) and is located near its outer edge. The thickness of the thinning portion (32) is less than the thickness of the unthinned area of ​​the cover plate body (34). Along the radial direction of the cover plate body (34), the thinning portion (32) is spaced apart from the electrode connecting portion (31). The protective member (40) covers the thinning portion (32).

7. The battery according to claim 6, characterized in that, The thinned portion (32) has an arc-shaped surface on the surface facing the cell (20) and / or away from the cell (20).

8. The battery according to claim 6, characterized in that, The protective member (40) has a puncture part (41) on the side facing the thinned part (32). The puncture part (41) is provided at the point where the thickness of the thinned part (32) is the smallest, and there is a gap between the puncture part (41) and the thinned part (32).

9. The battery according to claim 8, characterized in that, The protective member (40) has a recess (42) at the position corresponding to the puncture part (41), and the puncture part (41) is provided in the recess (42).

10. An electrical device comprising the battery as described in any one of claims 1 to 9.

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