Cover plate, deformation piece thereof and battery

Abstract

The utility model discloses a cover plate, a deformation piece thereof and a battery, and the deformation piece comprises a connecting part which is used for being electrically connected with a first pole of the cover plate and is an annular piece; the overturning part comprises a movable part and a mounting part, the movable part is an annular part, the outer periphery of the movable part is connected with the inner periphery of the connecting part, the mounting part is mounted on the inner periphery of the movable part, and the movable part can deform so that the deformation part can be switched between an initial state and a protection state; the protruding part is arranged on the surface of the side, close to the cover body of the cover plate, of the overturning part; when the deformation piece is in the initial state, the deformation piece is separated from the cover body. And in the process that the internal pressure of the battery reaches a preset value, the deformation piece is switched from the initial state to the protection state. According to the deformation piece, the small-size design of the battery can be realized, and the safety performance of the battery can be improved.

Description

Technical Field

[0001] This application relates to the field of battery technology, and more specifically, to a cover plate and its variants and a battery. Background Technology

[0002] With the rapid development of electric vehicles and renewable energy storage systems, the safety of power batteries and energy storage batteries, as core energy storage units, has become a critical indicator. During battery cycle charging and discharging, internal electrochemical reactions generate gases (such as hydrogen, oxygen, and methane). The accumulation of these gases can lead to increased internal pressure, causing serious safety problems such as expansion, leakage, and even thermal runaway, especially under extreme conditions such as high temperature, overcharging, and over-discharging, where the risks are further exacerbated. Furthermore, batteries may be affected by external impacts, vibrations, or changes in ambient temperature during use, further increasing safety risks. To address this issue, existing technologies often employ physical and mechanical structures such as flip-over plates as a protection mechanism. These irreversible flip-over actions release the gases accumulated inside the battery, thereby alleviating pressure and reducing safety risks. However, existing flip-over structures are typically located on the outside of a metal cover, resulting in an excessively large overall battery size. Utility Model Content

[0003] One objective of this application is to provide a deformable part for a cover plate that can solve the technical problem that the existing short-circuit protection structure requires a short-circuit electrical connection piece to be set on the outside of the battery cover plate, resulting in a large external space occupied by the terminal post.

[0004] Another object of this application is to provide a cover plate including the above-described modified part.

[0005] Another object of this application is to provide a battery including the aforementioned cover.

[0006] To achieve the above objectives, this application provides the following technical solutions.

[0007] A deformable member for a cover plate according to a first aspect embodiment of this application includes: a connecting portion for electrical connection with a first terminal of the cover plate, the connecting portion being an annular member; a flipping portion including a movable portion and a mounting portion, the movable portion being an annular member, the outer periphery of the movable portion being connected to the inner periphery of the connecting portion, the mounting portion being mounted on the inner periphery of the movable portion, the movable portion being deformable to switch the deformable member between an initial state and a protected state; and a protrusion provided on the side surface of the mounting portion of the cover plate near the cover plate; wherein, wherein When the deformable part is in the initial state, the inner periphery of the movable part extends toward the cover body away from the cover plate, and the end of the protrusion near the cover body does not extend beyond the end face of the connecting part near the cover body and is spaced apart from the cover body; during the process of the internal pressure of the battery reaching a preset value, the deformable part switches from the initial state to the protective state, the inner periphery of the movable part extends toward the cover body, and the end of the protrusion near the cover body is electrically connected to the cover body, so that the second electrode installed on the cover body and electrically connected to the cover body is short-circuited to the first electrode through the deformable part.

[0008] Optionally, the thickness of the portion of the movable part near the protrusion is greater than the thickness of the portion of the movable part near the connecting part.

[0009] Optionally, the flipping part is a circular sheet; or, the flipping part is an integrally molded part, and the flipping part and the connecting part and at least one of the protrusions adopt a separate installation structure.

[0010] A cover plate according to a second aspect of this application includes: a cover body having a first mounting hole and a second mounting hole; a first terminal and a second terminal, the first terminal being mounted in the first mounting hole and insulated from the cover body, the second terminal being mounted in the second mounting hole and electrically connected to the cover body, the first terminal and the second terminal having opposite polarities; and a deformable member disposed on the side of the cover body near the inside of the battery and electrically connected to the first terminal, the deformable member being a deformable member for a cover plate according to any of the above descriptions.

[0011] Optionally, the cover further includes: an insulating member located on the side of the cover body near the inside of the battery; the insulating member has a first through hole, a second through hole, and a third through hole; the first through hole corresponds to the position of the first mounting hole for mounting the first terminal; the second through hole corresponds to the position of the second mounting hole for mounting the second terminal; one end of the deformable member is electrically connected to the first terminal; and the other end of the deformable member corresponds to the position of the third through hole; wherein, when the deformable member is in the initial state, the deformable member is spaced apart from the cover body; when the deformable member is in the protected state, the protrusion passes through the third through hole and contacts the cover body to form a short circuit.

[0012] Optionally, the cover has a groove on the side near the inside of the battery, and the groove accommodates the protrusion when the protrusion contacts the cover after passing through the third through hole.

[0013] Optionally, the protrusion is a cylindrical structure extending toward the direction of the cover.

[0014] Optionally, the protrusion is a conical column structure, and the radial dimension of the protrusion gradually increases along the direction from the mounting part to the cover. The groove is a semi-circular groove, and the radial dimension of the groove at the position corresponding to the protrusion decreases as the radial dimension of the protrusion decreases.

[0015] A battery according to a third aspect of this application includes: a housing and a cover plate, wherein the cover plate is any of the cover plates described above, a receiving space is enclosed between the housing and the cover plate, the long side of the housing extends along the Z-axis direction, the wide side extends along the X-axis direction, and the thick side extends along the Y-axis direction; and an electrode assembly located in the receiving space.

[0016] Optionally, the electrode assembly (90) has a thickness of H in the Y-axis direction, and the moving part (421) has an average thickness of y in the X-axis direction, where 7 ≤ H / y ≤ 35.

[0017] According to an embodiment of this application, the deformable cover plate can be connected to the first terminal post. When the internal gas pressure of the battery increases during battery cycling, it can provide short-circuit protection for the battery, preventing phenomena such as battery thermal runaway and explosion, and improving battery safety. The deformable part of this application not only enables a small-size battery design but also improves battery safety performance.

[0018] Other features and advantages of this application will become clear from the following detailed description of exemplary embodiments with reference to the accompanying drawings. Attached Figure Description

[0019] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments of the present application and, together with their description, serve to explain the principles of the present application.

[0020] Figure 1 This is an assembly diagram of the housing and electrode assembly according to one embodiment of this application;

[0021] Figure 2 This is an exploded view of a cover plate according to an embodiment of this application;

[0022] Figure 3 This is an assembly diagram of the cover, insulating component, and adapter piece according to one embodiment of this application;

[0023] Figure 4 This is a schematic diagram of the assembly structure of the negative electrode post, the first connecting piece, the second connecting piece and the deformable part according to another embodiment of this application;

[0024] Figure 5 This is a schematic diagram of the assembly structure of the first connecting piece, the second connecting piece, and the deformable part according to an embodiment of this application;

[0025] Figure 6 This is an assembly diagram of the first connecting piece and the second connecting piece according to an embodiment of this application;

[0026] Figure 7 This is a structural schematic diagram of the inner side surface of the cover according to an embodiment of this application;

[0027] Figure 8 This is a cross-sectional view of a cover plate according to an embodiment of this application;

[0028] Figure 9 This is a partially enlarged cross-sectional view of a cover plate according to an embodiment of this application;

[0029] Figure 10 This is a schematic diagram of a modified part in its initial state according to an embodiment of this application;

[0030] Figure 11 This is a schematic diagram of a modified part in a protected state according to an embodiment of this application.

[0031] Attached icon number

[0032] Cover 10; First mounting hole 11; Second mounting hole 12; Groove 13;

[0033] First pole piece 21; Second pole piece 22;

[0034] Insulating component 30; First through hole 31; Second through hole 32; Third through hole 33;

[0035] Deformable part 40; Connecting part 41; Flipping part 42; Movable part 421; Mounting part 422; Protrusion 43;

[0036] First connecting piece 50;

[0037] Second connecting piece 60;

[0038] 71. Plastic on the positive electrode; 72. Plastic on the negative electrode; 73. Sealing ring; 74. Positive electrode connecting block; 75. Positive electrode adapter piece;

[0039] Casing 80;

[0040] Electrode assembly 90. Detailed Implementation

[0041] Various exemplary embodiments of the present application will now be described in detail with reference to the accompanying drawings. It should be noted that, unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the present application.

[0042] The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the scope of this application and its application or use.

[0043] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and equipment should be considered part of the specification.

[0044] In all the examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values.

[0045] It should be noted that similar labels and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be discussed further in subsequent figures.

[0046] The cover plate according to an embodiment of this application is described in detail below with reference to the accompanying drawings.

[0047] like Figures 1 to 11 As shown, the cover plate according to an embodiment of this application can be used for a battery, wherein the battery may include a housing 80 and a cover 10, and a receiving space is enclosed between the housing 80 and the cover 10, and an electrode assembly 90 is installed in the receiving space. The housing 80 has a long side, a wide side, and a thick side. For example, the long side of the housing 80 extends along the Z-axis direction, the wide side extends along the X-axis direction, and the thick side extends along the Y-axis direction. When multiple electrode assemblies 90 are installed in the housing 80, the multiple electrode assemblies 90 can be arranged sequentially along the Y-axis direction.

[0048] The cover 10 has a first mounting hole 11 and a second mounting hole 12 as electrode post holes, for example, the first mounting hole 11 and the second mounting hole 12 are spaced apart along the Z-axis direction. A first electrode post 21 is installed in the first mounting hole 11, and a second electrode post 22 is installed in the second mounting hole 12. The first electrode post 21 and the second electrode post 22 have opposite polarities. For example, the first electrode post 21 is a negative electrode post, and the second electrode post 22 is a positive electrode post, extending along the X-axis direction, and the first electrode post 21 and the second electrode post 22 are spaced apart along the Z-axis direction.

[0049] Furthermore, the cover 10 can be made of metal. The first terminal 21 is insulated from the cover 10 and electrically connected to the deformable member 40. The second terminal 22 is electrically connected to the cover 10. For example, the positive terminal is electrically connected to the cover 10, so the cover 10 is positively charged; the negative terminal is connected to the cover 10 through an insulating structure. In addition, the deformable member 40 is directly or indirectly connected to the negative terminal, and the deformable member 40 is negatively charged. In this embodiment, the deformable member 40 is located inside the battery. When the internal pressure of the battery is too high, the deformable member 40 connected to the first terminal 21 moves from a state spaced apart from the cover 10 towards the cover 10 under the action of air pressure until it contacts the cover 10, thus achieving short-circuit protection.

[0050] The following is a detailed description of the deformable part 40 for the cover plate according to an embodiment of this application.

[0051] like Figure 10 and Figure 11 As shown, the deformable member 40 for the cover plate according to an embodiment of this application includes: a connecting part 41, a flipping part 42, and a protrusion 43.

[0052] Specifically, the connecting part 41 is used for electrical connection with the first pole post 21 of the cover plate. The connecting part 41 is an annular part. The flipping part 42 includes a movable part 421 and a mounting part 422. The movable part 421 is an annular part. The outer periphery of the movable part 421 is connected to the inner periphery of the connecting part 41. The mounting part 422 is mounted on the inner periphery of the movable part 421. The movable part 421 can be deformed to switch the deformable part 40 between the initial state and the protected state. The protrusion 43 is provided on the side surface of the cover 10 near the cover plate of the mounting part 422.

[0053] When the deformable part 40 is in its initial state, the inner periphery of the movable part 421 extends toward the cover body 10 away from the cover plate, and the end of the protrusion 43 near the cover body 10 does not extend beyond the end face of the connecting part 41 near the cover body 10 and is spaced apart from the cover body 10.

[0054] During the process of the internal pressure of the battery reaching the preset value, the deformable part 40 switches from the initial state to the protection state, the inner periphery of the movable part 421 extends toward the direction close to the cover 10, and the end of the protrusion 43 close to the cover 10 is electrically connected to the cover 10, so that the second pole 22 installed on the cover 10 and electrically connected to the cover 10 is short-circuited to the first pole 21 through the deformable part 40.

[0055] In other words, the deformable part 40 for the cover plate according to the embodiments of this application mainly consists of a connecting part 41, a flipping part 42, and a protrusion 43. The cover plate includes a cover body 10 and the deformable part 40. In this embodiment, the connecting part 41 is an annular part, and the flipping part 42 mainly consists of a movable part 421 and a mounting part 422. The movable part 421 is an annular part, and its outer periphery is connected to the inner periphery of the connecting part 41. The mounting part 422 is disposed on the surface of the movable part 421, specifically on the side of the movable part 421 closest to the cover body 10. Furthermore, the connecting part 41 is electrically connected to the first pole post 21, and the two can be connected directly or indirectly.

[0056] Since the movable part 421 is deformable, during the process of deformation driven by the internal air pressure of the battery, the movable part 421 can drive the protrusion 43 to move towards the cover 10 through the mounting part 422. For example, the mounting part 422 is a solid circular sheet, and the protrusion 43 is located at the center of the mounting part 422 and extends towards the cover 10. For example, the height direction of the protrusion 43 extends approximately along the X-axis.

[0057] In this embodiment, the deformable part 40 mainly adopts a combination of a connecting part 41, a flipping part 42, and a protrusion 43. For example, the deformable part 40 is a flipping piece composed of a connecting part 41, a flipping part 42, and a protrusion 43. The lower end of the first electrode post 21 is installed on the connecting part, and the connecting part 41 is also provided on the connecting part. The movable part 421 is connected to the connecting part 41, and the mounting part 422 is connected to the movable part 421. The protrusion 43 is provided on the upper surface of the mounting part 422. When the internal pressure of the battery increases to a preset value, the inner edge of the movable part 421 moves toward a position close to the cover 10, and the mounting part 422 drives the protrusion 43 to move toward the cover 10, thereby making the protrusion 43 contact the cover 10. By using the mounting part 422 to cooperate with the movable part 421 and the protrusion 43, it is easier to reduce the difficulty of setting the protrusion 43 and to control the thickness of each part of the flipping part 42. For example, the thickness of the movable part 421 near the protrusion 43 can be controlled to be larger.

[0058] In this embodiment, when the deformable part 40 is applied to the battery, it is directly or indirectly connected to the first terminal 21. When the internal pressure of the battery is less than a preset value, the deformable part 40 is spaced apart from the cover 10. When the internal pressure of the battery increases to the preset value, the protrusion 43 can move under the pressure until it contacts the cover 10, thereby forming a short circuit. For example, when the internal air pressure of the battery increases, the flipping part 42 will deform towards the cover 10 until the protrusion 43 contacts the cover 10. Since the cover 10 is electrically connected to the positive terminal, the entire cover 10 is positively charged. The deformable part 40 is connected to the negative terminal, therefore, the deformable part 40 is negatively charged. So when the protrusion 43 contacts the cover 10 after deformation, a positive-negative short circuit will be formed, thereby protecting the battery.

[0059] In other words, when the deformable part 40 of this application is applied to a battery, the deformable part 40 can switch from the initial state to the protection state under the action of the gas pressure inside the battery. The deformable part 40 in the initial state and the protection state will be described in detail below.

[0060] First, when the deformable part 40 is in its initial state, the inner periphery of the movable part 421 extends toward the cover 10 away from the cover plate. The mounting part 422, which is connected to the inner periphery of the movable part 421, also moves away from the cover 10, and the protrusion 43 also moves away from the cover 10, thus separating the deformable part 40 from the cover 10. Furthermore, the end of the protrusion 43 near the cover 10 does not extend beyond the end face of the connecting part 41 near the cover 10 and is separated from the cover 10. For example, along the upward direction, the upper surface of the protrusion 43 is not higher than the upper end face of the connecting part 41, which increases the distance between the cover 10 and the protrusion 43, preventing accidental contact between the cover 10 and the protrusion 43. Additionally, it ensures that the flexible structure of the movable part 421 possesses complete elastic deformation potential energy. Moreover, the movable part 421 accumulates potential energy as gas is generated inside the battery. When the internal pressure of the battery reaches a set value, the movable part 421 can quickly flip, achieving slow absorption and fast reversal, resulting in a more stable flipping response.

[0061] Secondly, after the deformable part 40 switches from the initial state to the protected state, the inner periphery of the movable part 421 extends towards the cover 10, and the end of the protrusion 43 on the mounting part 422 near the cover 10 is electrically connected to the cover 10. For example, the upper end of the protrusion 43 located on the upper surface of the mounting part 422 contacts the lower side of the cover 10. At this time, the second pole 22 is short-circuited to the first pole 21 through the deformable part 40.

[0062] In the embodiments of this application, the deformable part 40 can be disposed inside the battery cell, and the movable part 421 deforms under pressure, with the protrusion 43 contacting the cover 10. This ensures the universality and consistency of the positive and negative terminals on the outside of the battery, and does not excessively occupy the outer surface space of the cover 10, which is beneficial for the standardized design when assembling battery cells. Moreover, since the deformable part 40 is disposed inside the battery cell, the terminals exposed on the outside of the battery cell do not need to be additionally enlarged or lengthened, and do not occupy the external space of the cover 10. In addition, since the deformable part 40 is disposed inside the battery cell, and there is no need to make openings in the cover 10 for assembly, the sealing design is greatly reduced, and safety and reliability are improved. Furthermore, since the deformable part 40 is disposed inside the battery cell, and the external terminals of the terminals do not need to be designed to be large, the assembly form of the terminals and the cover 10 is not limited to riveting. Based on the goal of low-cost design, injection molding can be used. That is to say, when using the deformable part 40 of the embodiments of this application, the assembly form of the terminals is not limited, and injection molding has a cost advantage over riveting structures.

[0063] Furthermore, traditional flip-plate designs, which are typically located on or outside the cover 10, place excessively high demands on welding reliability or require secondary sealing design. The modified component 40 structure of this embodiment, however, does not alter the original electrode sealing assembly structure, thus improving the overall sealing safety of the battery cell.

[0064] In some specific embodiments of this application, the end of the protrusion 43 away from the cover 10 is a plane, which can prevent the deformable part 40 from being too thick, for example, occupying a large area in the X-axis direction; or, the end of the protrusion 43 near the cover 10 is a plane, which facilitates increasing the contact area with the cover 10; or, the protrusion 43 is a cylindrical part, for example, the protrusion 43 is a cylindrical part extending along the X-axis direction, which facilitates contact with the cover 10; or, the movable part 421 is a ring part, which facilitates processing and installation, and facilitates the connection between the movable part 421, the mounting part 422, and the connecting part 41, in which case the connecting part 41 can be located on the outermost side of the movable part 421; or, the protrusion 43 is located at the center of the mounting part 422, for example, the protrusion 43 can be located at the center of the mounting part 422, which facilitates the balanced force distribution at multiple locations. It is understood that different design requirements can be met by implementing at least one of the above conditions.

[0065] According to one embodiment of this application, the thickness of the portion of the movable part 421 near the protrusion 43 is greater than the thickness of the portion of the movable part 421 near the connecting part 41. In this embodiment, by setting the thickness of the connecting part 41 to a non-uniform thickness, the movable part 421 is made easier to flip.

[0066] In some specific embodiments of this application, the flipping part 42 is a circular sheet with a circular outer contour, which is convenient for processing; or, the flipping part 42 is a one-piece molded part, and at least one of the flipping part 42, the connecting part 41, and the protrusion 43 adopts a separate mounting structure. For example, the connecting part 41 and the flipping part 42 are one-piece molded parts, and a separate mounting structure is adopted between them and the protrusion 43; or, for another example, the protrusion 43 and the flipping part 42 are one-piece molded parts, and a separate mounting structure is adopted between them and the connecting part 41. It can be seen that the deformable part 40 can be manufactured in a variety of ways.

[0067] This application also discloses a cover plate, including: a cover body 10, a first terminal 21, a second terminal 22, and a deformable member 40. The cover body 10 can be a metal part, and the cover body 10 is provided with a first mounting hole 11 and a second mounting hole 12. The first terminal 21 is mounted in the first mounting hole 11 and is insulated from the cover body 10, and the second terminal 22 is mounted in the second mounting hole 12 and is electrically connected to the cover body 10. The first terminal 21 and the second terminal 22 have opposite polarities. The deformable member 40 is disposed on the side of the cover body 10 near the inside of the battery and is electrically connected to the first terminal 21 mounted in the first mounting hole 11. The deformable member 40 is the deformable member 40 for the cover plate according to any of the above embodiments. Since the deformable member 40 for the cover plate according to the embodiments of this application has the above advantages, such as high safety, the cover plate of the embodiments of this application also has the above advantages, which will not be elaborated here.

[0068] In some specific embodiments of this application, the cover plate further includes: an insulating member 30, located on the side of the cover 10 near the inside of the battery. The insulating member 30 is provided with a first through hole 31, a second through hole 32, and a third through hole 33. The first through hole 31 corresponds to the position of the first mounting hole 11 to install the first terminal 21, which is insulated from and connected to the cover 10. The second through hole 32 corresponds to the position of the second mounting hole 12 to install the second terminal 22, which is electrically connected to the cover 10 and has the opposite polarity to the first terminal 21. One end of the deformable member 40 is electrically connected to the first terminal 21, and the other end of the deformable member 40 corresponds to the position of the third through hole 33. For example, one end of the deformable member 40 is located on the side of the insulating member 30 away from the cover 10 and is connected to and electrically connected to the first terminal 21. When the deformable part 40 is in the initial state, the deformable part 40 is separated from the cover 10. When the deformable part 40 is in the protected state, another end of the deformable part 40 passes through the third through hole 33 and contacts the cover 10 to form a short circuit.

[0069] In other words, an insulating component 30 is provided on the side of the cover 10 near the inside of the battery, for example, the insulating component 30 is arranged approximately parallel to the cover 10. The insulating component 30 can be made of plastic sheet or the like, and the use of a plate-like structure can reduce the space occupied. The insulating component 30 is provided with a first through hole 31, a second through hole 32, and a third through hole 33, for example, the first through hole 31, the second through hole 32, and the third through hole 33 are spaced apart along the Z-axis, and the third through hole 33 is located between the first through hole 31 and the second through hole 32. The first through hole 31 corresponds to the position of the first mounting hole 11, and the second through hole 32 corresponds to the position of the second mounting hole 12, for example, they correspond in the X-axis direction. That is to say, the inner end of the first electrode post 21 can pass through the first mounting hole 11 and the first through hole 31 in sequence and then connect to the corresponding electrode tab. Similarly, the inner end of the second electrode post 22 can also pass through the second mounting hole 12 and the second through hole 32 in sequence and then connect to the corresponding electrode tab.

[0070] Furthermore, the insulating member 30 has a third through hole 33, and the protrusion 43 corresponds to the third through hole 33, for example, in the X-axis direction, allowing the protrusion 43 to contact the cover 10. When the internal pressure of the battery is less than a preset value, the deformable member 40 is spaced apart from the cover 10. When the internal pressure of the battery increases to the preset value, the protrusion 43 can extend out of the third through hole 33 under the pressure and contact the cover 10 to form a short circuit. For example, when the internal air pressure of the battery increases, the movable part 421 will deform in the direction of the cover 10, and at the same time, the protrusion 43 will pass through the third through hole 33 until it contacts the cover 10. This is equivalent to the first terminal 21 and the second terminal 22 forming a circuit through the cover 10 and the deformable member 40; causing a short circuit between the first terminal 21 and the second terminal 22, that is, a positive and negative short circuit, which can protect the battery using the cover plate of this application embodiment.

[0071] Specifically, since the deformable part 40 includes a flipping part 42 and a protrusion 43, the flipping part 42 includes a movable part 421 and a mounting part 422, and the protrusion 43 is located on one side surface of the mounting part 422, when the internal pressure of the battery increases to a preset value, the movable part 421 moves toward a position close to the cover 10 until the protrusion 43 extends out of the third through hole 33 and contacts the cover 10. That is, the movable part 421 is used to deform as the air pressure increases during battery cycling. For example, the connector includes a first connecting piece 50 and a second connecting piece 60. The lower end of the first terminal 21 is mounted on the first connecting piece 50, and the first connecting piece 50 is connected to the second connecting piece 60. The deformable part 40 is disposed on the second connecting piece 60. When the internal pressure of the cell increases, it deforms and flips upward, and the protrusion 43 contacts the cover 10 to form a current path loop, realizing short-circuit protection under overcharge. For example, the connecting portion 41 is located in the middle of the second connecting piece 60 or near the Z-axis end. The connecting portion 41 connects the second connecting piece 60 and the movable portion 421. The protrusion 43 is located on the upper surface of the mounting portion 422, and the cylindrical protrusion 43 extends approximately along the X-axis direction in the axial direction. In this embodiment, by setting the deformable member 40 on the connecting piece or the second connecting piece 60, that is, on the extension structure of the first electrode post 21, the deformable member 40 is inside the battery, which does not affect the electrode post terminal structure outside the battery, does not occupy external space, and does not affect battery pack assembly.

[0072] In addition, the cover 10 is electrically connected to the second electrode post 22. For example, the cover 10 is made of a conductive metal material, and the insulating plate 30 is located on the side of the cover 10 closer to the inside of the battery. That is, the insulating plate 30 is placed between the cover 10 and the electrode assembly 90 inside the battery, which can play an insulating role and prevent short circuit between the positive and negative electrodes. Secondly, the insulating plate 30, through structural cooperation, can ensure that the first electrode post 21 and the second electrode post 22 are fixed on the cover 10. In addition, the insulating plate 30 is placed inside the battery casing, which can limit the electrode assembly 90 and prevent the electrode assembly 90 from moving in the casing and colliding, thus preventing damage to the electrode assembly 90.

[0073] Optionally, along the direction from the cover 10 to the insulator 30, for example along the X-axis, the orthographic projection of the deformable member 40 is located inside the third through hole 33. For example, the outer contour of the deformable member 40 is circular, and the radius of the third through hole 33 is not less than the radius of the deformable member 40. In this embodiment, the difficulty of contacting the deformable member 40 with the cover 10 can be reduced.

[0074] Optionally, when the deformable part 40 is in the initial state, at least a portion of the movable part 421 forms an arc-shaped bend with an opening facing the cover 10; when the deformable part 40 is in the protected state, at least a portion of the movable part 421 forms an arc-shaped bend with an opening away from the cover 10, which can reduce the difficulty of the movable part 421 being subjected to force and flipping.

[0075] In some specific embodiments of this application, the cover 10 is provided with a groove 13 on the side near the inside of the battery. When the protrusion 43 passes through the third through hole 33 and comes into contact with the cover 10, the groove 13 accommodates the protrusion 43.

[0076] In some specific embodiments of this application, the protrusion 43 is a columnar structure extending toward the cover 10, which is not only easy to process and manufacture, but also easy to insert into the groove 13, thus simplifying the structure of the groove 13.

[0077] According to one embodiment of this application, the protrusion 43 is a tapered column structure extending toward the cover 10. Along the direction from the mounting portion 422 toward the cover 10, the radial dimension of the protrusion 43 gradually increases. The groove 13 is a semi-circular groove, and the radial dimension of the groove 13 at the position corresponding to the protrusion 43 decreases as the radial dimension of the protrusion 43 decreases. That is, the radial dimension of the end of the protrusion 43 near the cover 10 is smaller than the radial dimension of the portion where the protrusion 43 connects to the mounting portion 422. For example, if the protrusion 43 extends vertically, its upper end extends toward the cover 10 and has a small radial dimension, while its lower end connects to the mounting portion 422 and has a large radial dimension. Furthermore, the groove 13 is a semi-circular groove, and the radial dimension of the groove 13 at different positions corresponding to the protrusion 43 decreases as the height of the protrusion 43 increases.

[0078] In other words, the protrusion 43 is a conical column structure, and its height in the X-axis direction can be defined as L. A groove 13 is provided at the corresponding position on the aluminum sheet, and the radius of the groove 13 is R1. The height of the protrusion 43 is divided into L0, L1, and L2; L0 > L1 > L2, and the radius corresponding to L0 is R3; the radius corresponding to L1 is R2, and the radius corresponding to L2 is R1. The relationship between the radii satisfies R3 < R2 < R1. This allows the protrusion 43 to contact the aluminum sheet more firmly when the movable part 421 is flipped, making it less likely to melt and cause a short circuit. If the gas pressure inside the battery is at a critical value near a threshold, it can prevent incomplete short circuits caused by the protrusion 43 not contacting the cover 10 tightly.

[0079] According to one embodiment of this application, the cover plate further includes a connector, which connects the deformable member 40 and the first pole post 21 respectively. That is, the deformable member 40 can be indirectly connected to the first pole post 21 via the connector. In this embodiment, the connector acts as a bridge, reducing the difficulty of connecting the deformable member 40 and the first pole post 21.

[0080] According to one embodiment of this application, the connector is located on the side of the cover 10 near the inside of the battery. The connector, for example, is located on the side of the insulating member 30 away from the cover 10, for example, the connector is located below the insulating member 30 in the X-axis direction. A deformable member 40 is provided on the connector, which is used to connect to the first terminal 21. For example, the connector is located at one end of the first terminal 21 near the inside of the battery, and the deformable member 40 is also provided on the connector. In this embodiment, the deformable member 40 can be provided on the connector, which can reduce the space occupied by the deformable member 40. Optionally, one end of the connector in the Z-axis direction is connected to the end of the first terminal 21 in the X-axis direction, and the deformable member 40 is provided in the middle of the connector or in the region near the other end in the Z-axis direction, which can reduce the size of the battery in the Z-axis direction.

[0081] In some specific embodiments of this application, the connector includes: a first connecting piece 50 and a second connecting piece 60. The first connecting piece 50 is used to connect to the first pole post 21. For example, the first connecting piece 50 is located on the side of the insulating member 30 away from the cover 10. The second connecting piece 60 is connected to the first connecting piece 50. For example, the second connecting piece 60 and the first connecting piece 50 are located on the same side of the insulating member 30. A deformable member 40 is provided on the second connecting piece 60. For example, the second connecting piece 60 is a rectangular plate with a circular through hole in it, and the deformable member 40 is disposed in the circular through hole. As another example, the second connecting piece 60 is located above the left end of the first connecting piece 50. The second connecting piece 60 and the first connecting piece 50 are stamped as a single piece, and the upper surface of the right end of the first connecting piece 50 is connected to the lower end of the first pole post 21. For example, the second connecting piece 60 is located to the left of the first connecting piece 50, the right end of the second connecting piece 60 is connected to the left end of the first connecting piece 50, the upper surface of the middle part of the first connecting piece 50 is connected to the lower end of the first pole post 21, and the first connecting piece 50 and the second connecting piece 60 are welded together.

[0082] In other words, the connector in this embodiment mainly consists of a first connecting piece 50 and a second connecting piece 60. The first connecting piece 50 and the second connecting piece 60 can be simultaneously located on the side of the insulating member 30 away from the cover 10, for example, below the insulating member 30. The first connecting piece 50 can be connected to the first pole post 21, for example, directly. A deformable member 40 is mounted or provided on the second connecting piece 60, and the second connecting piece 60 can function as a mounting carrier or extension block. The second connecting piece 60 is also connected to the first connecting piece 50, and can simultaneously achieve indirect connection and serve as a mounting carrier. Furthermore, the insulating member 30 can be located between the first connecting piece 50 and the cover 10, providing insulation and circuit breaking under normal operating conditions. Simultaneously, by using sheet-like first connecting pieces 50 and 60, their thickness can be reduced, for example, in the X-direction, thus reducing the occupied volume. In addition, the second connecting piece 60 can function as an extension piece, for example, extending in the Z-axis direction, preventing interference between the deformable member 40 and the first pole post 21, and facilitating the installation of the deformable member 40. Furthermore, by setting the deformable part 40 on the connector, that is, on the extension structure of the first pole post 21, the deformable part 40 is inside the battery, which does not easily affect the pole post terminal structure outside the battery, thus avoiding occupying space outside and affecting battery pack assembly.

[0083] Optionally, one end of the first connecting piece 50 in the Z-axis direction is connected to the end of the first pole post 21 in the X-axis direction, and the other end of the first connecting piece 50 in the Z-axis direction is connected to one end of the second connecting piece 60 in the Z-axis direction. The deformable member 40 is disposed on the second connecting piece 60 and extends approximately along the X-axis direction. By adopting a sheet-like structure, the space occupied by the connecting piece and the deformable member 40 in the X-axis direction can be reduced. By adopting the second connecting piece 60, it is beneficial for the deformable member 40 to be deformed under force.

[0084] This application also discloses a battery, including: a housing 80, a cover plate, and an electrode assembly 90. The cover plate is the cover plate of any of the above embodiments. A receiving space is enclosed between the housing 80 and the cover body 10 of the cover plate. The long side of the housing 80 extends along the Z-axis direction, the wide side extends along the X-axis direction, and the thick side extends along the Y-axis direction. The electrode assembly 90 is located in the receiving space and has two tabs. The two tabs are respectively connected to the first terminal 21 and the second terminal 22 through adapter pieces.

[0085] For example, a sodium-ion single-cell battery includes a casing 80, a cover plate, and an electrode assembly 90. The casing 80 is an aluminum casing, optionally formed by stretching and having a semi-closed opening. The cover plate includes a cover body 10 and an insulating member 30. The cover body 10 can be placed over the opening of the aluminum casing to seal the battery casing 80. The electrode assembly 90 is housed within the aluminum casing. The electrode assembly 90 includes multiple cores formed by winding a positive electrode sheet, a separator, and a negative electrode sheet. The positive electrode sheet includes a positive electrode active material, which can be selected from one or more of layered oxides, polyanionic compounds, and Prussian blue compounds. The negative electrode sheet includes a negative electrode active material, which can be selected from one or more of hard carbon and soft carbon. Since layered oxide positive electrodes have a high theoretical specific capacity and an open layered structure, and hard carbon has high specific capacity and good sodium storage performance, the batteries in this embodiment have high energy density and good rate performance; therefore, hard carbon is preferred.

[0086] According to one embodiment of this application, layered oxide is used as the main positive electrode material. Layered oxide has a large gas production and slightly lower stability. When gas is continuously produced during battery cycling, it will cause changes in the gas pressure inside the battery. When the gas pressure inside the battery increases, the flipping part 42 will deform. The flipping part 42 will move towards the cover 10, and the protrusion 43 will pass through the third through hole 33 on the insulating member 30 and then contact the cover 10. Thus, a short circuit structure is formed.

[0087] In one embodiment of this application, the battery cover 10, negative electrode post, and deformable part 40 are made of the same material. For example, the negative electrode post can be made of aluminum, the first connecting piece 50 connected to the negative electrode post is also made of aluminum, and the second connecting piece 60 connected to the first connecting piece 50 and the deformable part 40 are also made of aluminum. In this case, the negative electrode post, the first connecting piece 50, the second connecting piece 60, and the flip piece are all made of the same material, which can improve the reliability of the welding connection. It should be noted that, compared with lithium batteries, lithium batteries require the use of copper electrode posts, etc., and cannot use aluminum as the negative electrode current collector. Therefore, when the battery in this embodiment is a sodium-ion battery, the cost of the structural components can be reduced.

[0088] Optionally, such as Figure 3As shown, the battery also includes a positive electrode adapter 75. One side of the positive electrode adapter 75 is connected to the positive electrode connecting block 74 on the positive electrode post, and the other side is connected to the positive electrode tab of the electrode assembly 90. For example, in the X-axis direction, the upper surface of the positive electrode adapter 75 is connected to the positive electrode connecting block 74 on the positive electrode post, and the lower surface is connected to the positive electrode tab. The second connecting piece 60 is connected to the first connecting piece 50 and also to the negative electrode tab of the electrode assembly 90. This avoids occupying internal battery assembly space by using a separate connection structure. For example, one end of the second connecting piece 60 in the Z-axis direction is connected to the first connecting piece 50, and the other end of the second connecting piece 60 in the X-axis direction is connected to the negative electrode tab. In addition, the positive electrode adapter 75 is located on the side of the insulating member 30 closer to the inside of the battery, for example, located below the insulating member 30 in the X-axis direction.

[0089] The following detailed description uses the positive electrode adapter 75 in the adapter piece as an example, combined with a specific embodiment.

[0090] One side of the positive electrode adapter 75 is connected to the connecting block on the positive electrode post, and the other side is connected to the positive electrode tab of the electrode assembly 90. For example, in the X-axis direction, the upper surface of the positive electrode adapter 75 is connected to the connecting block on the positive electrode post, and the lower surface is connected to the positive electrode tab. In addition, the positive electrode adapter 75 is located on the side of the insulating member 30 closer to the inside of the battery, for example, located below the insulating member 30 in the X-axis direction.

[0091] Optionally, a sealing ring 73 is also provided between the positive terminal and the cover 10 for sealing. Optionally, a sealing ring 73 is also provided between the negative terminal and the cover 10 for sealing and insulation.

[0092] This application also discloses a battery, comprising: a housing 80, a cover plate, and an electrode assembly 90. The cover plate is the cover plate of any of the above embodiments. A receiving space is enclosed between the housing 80 and the cover body 10 of the cover plate. The electrode assembly 90 is located in the receiving space and has two tabs. The tab with the same polarity as the first terminal 21 is connected to the first terminal 21 through a connector, and the tab with the opposite polarity to the first terminal 21 is connected to the second terminal 22 through an adapter. For example, the second connecting piece 60 is connected to the first connecting piece 50 and also to the negative tab of the electrode assembly 90, which can avoid occupying the internal assembly space of the battery by setting up a separate connection structure. For example, one end of the second connecting piece 60 in the Z-axis direction is connected to the first connecting piece 50, and one end of the second connecting piece 60 in the X-axis direction is connected to the negative tab.

[0093] According to one embodiment of this application, the flipping threshold of the movable part 421 is related to the thickness of the electrode assembly 90. When the thickness of the electrode assembly 90 is greater, the battery capacity is greater, the gas production during the cycle is greater, and the gas production speed is faster. The thickness of the electrode assembly 90 in the Y-axis direction is defined as H, and the thickness of the movable part 421 in the X-axis direction is defined as y, where 7 ≤ H / y ≤ 35. For example, by limiting 7 ≤ H / y ≤ 35, such as the ratio of H to y being 7, 8, 10, 12, 15, 20, 25, 30, 32, or 35, it can be ensured that the movable part 421 accurately flips when the internal gas pressure of the battery increases, thereby improving battery safety and stability. In addition, it can also prevent the size of the casing 80 from becoming too large due to the setting of the deformable part 40 and the electrode assembly 90.

[0094] The battery of this application will be described in detail below with reference to specific embodiments and comparative examples.

[0095] In Example 1, the thickness H1 of the electrode assembly is 30; the average thickness y1 of the moving part 421 is 2; and the ratio of H1 / y1 is 15.

[0096] In Example 2, the thickness H2 of the electrode assembly is 25, and the average thickness y2 of the moving part 421 is 2; the ratio of H2 / y2 is 12.5.

[0097] In Example 3, the thickness H5 of the electrode assembly is 25, and the average thickness y5 of the moving part 421 is 2.5; the ratio of H5 / y5 is 10.

[0098] In Example 4, the thickness H3 of the electrode assembly is 14, and the average thickness y3 of the moving part 421 is 2; the ratio of H3 / y3 is 7.

[0099] In Example 5, the electrode assembly has a thickness H4 of 24.5 and an average thickness y4 of 0.7 for the moving part 421; the ratio of H4 / y4 is 35.

[0100] Overcharge tests were performed on the batteries from Examples 1-5 described above:

[0101] At 25°C, the battery cells were charged at a constant current and constant voltage of 0.33C to the upper limit cutoff voltage of 3.85V, and then charged at a constant voltage to a current of 0.05C. The battery cells were then charged for 1 hour under the following conditions or the voltage of the battery cells reached 1.5 times the upper limit cutoff voltage. The test results are shown in Table 1 below.

[0102] Table 1

[0103]

[0104] As can be seen from the results in Table 1, when the ratio of the thickness of the electrode assembly 90 to the thickness of the flipping part of the flipping sheet is in the range of 7-35, the flipping sheet can flip normally, and the size of the assembled battery is small.

[0105] In summary, the deformable cover plate according to the embodiments of this application can be connected to the first terminal post. When the internal gas pressure of the battery increases during battery cycling, it can provide short-circuit protection for the battery, avoiding phenomena such as battery thermal runaway and explosion, and improving battery safety. The deformable part of this application not only enables a small-size battery design but also improves battery safety performance.

[0106] While specific embodiments of this application have been described in detail by way of examples, those skilled in the art should understand that the above examples are for illustrative purposes only and are not intended to limit the scope of this application. Those skilled in the art should understand that modifications can be made to the above embodiments without departing from the scope and spirit of this application. The scope of this application is defined by the appended claims.

Claims

1. A deformable part (40) for a cover plate, characterized in that, include: A connecting part (41) is used for electrical connection with the first pole (21) of the cover plate, and the connecting part (41) is an annular part; The flipping part (42) includes a movable part (421) and a mounting part (422). The movable part (421) is a ring-shaped part. The outer periphery of the movable part (421) is connected to the inner periphery of the connecting part (41). The mounting part (422) is mounted on the inner periphery of the movable part (421). The movable part (421) can be deformed to switch the deformable part (40) between an initial state and a protected state. A protrusion (43) is provided on one side surface of the cover (10) of the mounting part (422) near the cover plate; When the deformable part (40) is in the initial state, the inner periphery of the movable part (421) extends toward the cover body (10) away from the cover plate, and the end of the protrusion (43) near the cover body (10) does not extend beyond the end face of the connecting part (41) near the cover body (10) and is spaced apart from the cover body (10). During the process of the internal pressure of the battery reaching the preset value, the deformable part (40) switches from the initial state to the protective state, the inner periphery of the movable part (421) extends toward the cover (10), and the end of the protrusion (43) near the cover (10) is electrically connected to the cover (10) so that the second pole (22) installed on the cover (10) and electrically connected to the cover (10) is short-circuited to the first pole (21) through the deformable part (40).

2. The deformable member (40) for the cover plate according to claim 1, characterized in that, The thickness of the portion of the movable part (421) near the protrusion (43) is greater than the thickness of the portion of the movable part (421) near the connecting part (41).

3. The deformable member (40) for the cover plate according to claim 1, characterized in that, The flipping part (42) is a circular sheet; or, the flipping part (42) is an integrally molded part, and the flipping part (42) and at least one of the connecting part (41) and the protrusion (43) adopt a separate installation structure.

4. A cover plate, characterized in that, include: The cover (10) is provided with a first mounting hole (11) and a second mounting hole (12). The first pole (21) and the second pole (22) are installed in the first mounting hole (11) and are insulated from the cover (10). The second pole (22) is installed in the second mounting hole (12) and is electrically connected to the cover (10). The first pole (21) and the second pole (22) have opposite polarities. A deformable part (40) is disposed on the side of the cover (10) near the inside of the battery and electrically connected to the first terminal post (21). The deformable part (40) is a deformable part (40) for a cover plate according to any one of claims 1-3.

5. The cover plate according to claim 4, characterized in that, Also includes: An insulating component (30) is located on the side of the cover (10) near the inside of the battery. The insulating component (30) is provided with a first through hole (31), a second through hole (32) and a third through hole (33). The first through hole (31) corresponds to the position of the first mounting hole (11) to install the first terminal (21). The second through hole (32) corresponds to the position of the second mounting hole (12) to install the second terminal (22). One end of the deformable component (40) is electrically connected to the first terminal (21), and the other end of the deformable component (40) corresponds to the position of the third through hole (33). When the deformable part (40) is in the initial state, the deformable part (40) is spaced apart from the cover (10). When the deformable part (40) is in the protective state, the protrusion (43) passes through the third through hole (33) and contacts the cover (10) to form a short circuit.

6. The cover plate according to claim 5, characterized in that, The cover (10) has a groove (13) on the side near the inside of the battery. When the protrusion (43) passes through the third through hole (33) and comes into contact with the cover (10), the groove (13) accommodates the protrusion (43).

7. The cover plate according to claim 6, characterized in that, The protrusion (43) is a cylindrical structure extending toward the cover (10).

8. The cover plate according to claim 7, characterized in that, The protrusion (43) is a conical column structure. Along the direction from the mounting part (422) to the cover (10), the radial dimension of the protrusion (43) gradually increases. The groove (13) is a semi-circular groove. The radial dimension of the groove (13) at the position corresponding to the protrusion (43) decreases as the radial dimension of the protrusion (43) decreases.

9. A battery, characterized in that, include: The housing (80) and the cover plate, wherein the cover plate is the cover plate according to any one of claims 4-8, and a receiving space is enclosed between the housing (80) and the cover body (10) of the cover plate, wherein the long side of the housing (80) extends along the Z-axis direction, the wide side extends along the X-axis direction, and the thick side extends along the Y-axis direction; Electrode assembly (90) is located in the containment space.

10. The battery according to claim 9, characterized in that, The electrode assembly (90) has a thickness of H in the Y-axis direction, and the moving part (421) has an average thickness of y in the X-axis direction, where 7 ≤ H / y ≤ 35.

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