Adapter plate, cover plate assembly and battery cell

Abstract

The application provides a switching piece, a cover plate assembly and a battery cell. The switching piece includes a conductive main body, a first connecting part and a second connecting part. The first connecting part is used for connecting a pole of the battery cell. The second connecting part is used for connecting a tab of the battery cell. A slot hole is arranged on the conductive main body and located between the first connecting part and the second connecting part. The depth of the slot hole is less than or equal to the thickness of the conductive main body. The slot hole is filled with a conductive material. The melting point of the conductive material is less than the melting point of the material constituting the conductive main body. The switching piece, the cover plate assembly and the battery cell provided by the application are simple in structure, convenient to manufacture, high in conductivity, high in mechanical performance and good in safety.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to an adapter plate, a cover plate assembly, and a battery cell. Background Technology

[0002] The adapter plate is a component in a battery cell that connects the tabs and terminals. To prevent thermal runaway when the battery cell is short-circuited, the adapter plate usually has a narrow flow section or a fusible section to break the circuit. However, this reduces the conductivity and mechanical strength of the adapter plate. Therefore, there is an urgent need for an adapter plate that combines high conductivity and high mechanical strength, and can quickly fuse in the event of a battery cell short circuit. Utility Model Content

[0003] In view of this, the purpose of this application is to provide an adapter plate, a cover plate assembly, and a battery cell to solve the related problems mentioned in the background art.

[0004] A first aspect of this application provides an adapter plate, comprising: a conductive body including a first connecting portion and a second connecting portion, the first connecting portion being used to connect a terminal post of a battery cell, and the second connecting portion being used to connect a tab of the battery cell; a slot disposed on the conductive body, located between the first connecting portion and the second connecting portion, the depth of the slot being less than or equal to the thickness of the conductive body; the slot being filled with a conductive material, the melting point of the conductive material being less than the melting point of the material constituting the conductive body.

[0005] Furthermore, the slot is a through hole extending along the thickness direction of the conductive body.

[0006] Furthermore, the current-carrying width of the through hole is a, the current-carrying width of the conductive body at the through hole is c, and the through hole satisfies a / c≤65%.

[0007] Furthermore, the depth of the through-hole and the thickness of the conductive body are both b, the current carrying capacity of the conductive body material is T1, the current carrying capacity of the conductive material is T2, the maximum discharge power of the battery cell is Pmax, the lower voltage limit of the battery cell is Vmin, and the short-circuit current of the battery cell is Isc; the through-hole satisfies a×b×T2+ (ca)×b×T1>Pmax / Vmin, and also satisfies a×b×T2+ (ca)×b×T1 <Isc。

[0008] Furthermore, the slot is a through groove extending in a direction perpendicular to the thickness of the conductive body, and the depth of the through groove is less than the thickness of the conductive body.

[0009] Furthermore, the depth of the through groove is b1, the thickness of the conductive body is b, and the through groove satisfies b1 / b≤50%.

[0010] Further, the current-carrying width of the through-slot is c, the current-carrying capacity of the conductive body material is T1, the current-carrying capacity of the conductive material is T2, the maximum discharge power of the battery cell is Pmax, the lower voltage limit of the battery cell is Vmin, and the short-circuit current of the battery cell is Isc; the through-slot satisfies c×b1×T2 + c×(b-b1)×T1 > Pmax / Vmin, and also satisfies c×b1×T2 + c×(b-b1)×T1 <Isc。

[0011] Furthermore, the conductive body includes two second connecting portions, and each second connecting portion and the first connecting portion are provided with at least one slot.

[0012] A second aspect of this application provides a cover plate assembly, including a cover plate body connected to an adapter piece as described in the first aspect above.

[0013] A third aspect of this application provides a battery cell including a housing connected to a cover assembly as described in the second aspect above, and an electrode assembly disposed inside the housing.

[0014] As can be seen from the above description, the adapter plate, cover plate assembly, and battery cell provided in this application include: a conductive body comprising a first connecting portion and a second connecting portion, the first connecting portion being used to connect the terminal post of the battery cell, and the second connecting portion being used to connect the tab of the battery cell; a slot disposed on the conductive body, located between the first connecting portion and the second connecting portion, the depth of the slot being less than or equal to the thickness of the conductive body; the slot being filled with a conductive material, the melting point of which is lower than the melting point of the material constituting the conductive body. By setting a slot between the first connecting portion and the second connecting portion, and placing a conductive material with a lower melting point inside the slot, the conductive material can be preferentially melted when the short-circuit temperature of the battery cell rises, thereby reducing the overcurrent cross-sectional area at the slot, increasing the resistance, further increasing the temperature at that point, and thus melting the conductive body at that point, achieving circuit break protection. The conductive material filling the slot does not reduce the overcurrent cross-sectional area when the battery cell is operating normally, avoiding affecting the energy efficiency of the battery, resulting in low heat generation when the battery cell is operating normally, and ensuring the cycle life of the battery cell. The conductive material and the conductive body fit together at the slot, resulting in good mechanical properties that meet the strength requirements of the battery cell during use. This adapter plate, cover assembly, and battery cell have a simple structure, are easy to manufacture, have high conductivity, high mechanical properties, and good safety. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in this application or related technologies, the drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a top view of an adapter piece in an embodiment of this application;

[0017] Figure 2 for Figure 1 Side view of the intermediate connector;

[0018] Figure 3 for Figure 1 A schematic diagram of the cross-section along the AA direction;

[0019] Figure 4 This is a top view of another adapter piece in an embodiment of this application;

[0020] Figure 5 for Figure 4 Schematic diagram of the cross section in the BB direction;

[0021] Figure 6 This is a schematic diagram of the structure of a cover plate assembly in an embodiment of this application;

[0022] Figure 7 This is a schematic diagram of the structure of a battery cell in an embodiment of this application.

[0023] Reference numerals: 1. Conductive body; 1-1. First connecting part; 1-2. Second connecting part; 1-3. Slot; 1-4. Conductive material; 2. Cover plate body; 3. Housing. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with specific embodiments and the accompanying drawings.

[0025] It should be noted that, unless otherwise defined, the technical or scientific terms used in the embodiments of this application should have the ordinary meaning understood by one of ordinary skill in the art to which this application pertains. The terms "first," "second," and similar terms used in the embodiments of this application do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are only used to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0026] To prevent thermal runaway when the battery cell is short-circuited, the adapter plate is usually provided with a narrow flow section or a fusible section to break the circuit, but this will reduce the conductivity and mechanical strength of the adapter plate.

[0027] Specifically, some technologies incorporate narrow current-carrying regions on the cell adapter plate. This is achieved by punching holes or slots of a specific size into the adapter plate or reducing the width of a specific area to form a narrow current-carrying section. This results in a smaller current-carrying cross-sectional area and higher resistance in this region. When the cell short-circuits, this accelerates the temperature rise in this area, causing the adapter plate to melt and break the circuit. However, during normal cell operation, the high resistance of this adapter plate also affects the cell's energy efficiency and generates significant heat, reducing the cell's cycle life.

[0028] In some technologies, the adapter piece is split into two sections, which are connected by a fusible link made of a low-melting-point material. The fusible link material is, for example, lead-tin alloy, cadmium-indium-tin alloy, or bismuth-tin alloy. When the current is too large, it can melt quickly. However, the fusible link material has lower strength than the adapter piece material, which makes it difficult to meet the strength requirements during the use of the battery cell. In addition, the conductivity of the fusible link material is also significantly reduced compared to the adapter piece material, which will affect the working performance of the battery cell.

[0029] Therefore, there is an urgent need for an adapter that combines high conductivity and high mechanical properties, and can quickly melt when the battery cell is short-circuited.

[0030] The following describes specific embodiments in conjunction with the appendix. Figures 1 to 7 The technical solution of this application will be described in further detail.

[0031] In some embodiments of this application, an adapter is provided, comprising: a conductive body 1, including a first connecting portion 1-1 and a second connecting portion 1-2, wherein the first connecting portion 1-1 is used to connect the terminal post of a battery cell, and the second connecting portion 1-2 is used to connect the tab of the battery cell; a slot 1-3 is disposed on the conductive body 1, located between the first connecting portion 1-1 and the second connecting portion 1-2, wherein the depth of the slot 1-3 is less than or equal to the thickness of the conductive body 1; the slot 1-3 is filled with a conductive material 1-4, wherein the melting point of the conductive material 1-4 is less than the melting point of the material constituting the conductive body 1.

[0032] like Figure 1 The image shown is a top view of an adapter plate. The adapter plate includes a conductive body 1, which may be, for example, a metal plate, and its shape may be, for example, rectangular, but is not specifically limited. The conductive body 1 includes a first connecting portion 1-1 and a second connecting portion 1-2, as shown... Figure 1 As shown, a first connecting part 1-1 is connected to one side of the conductive body 1. The first connecting part 1-1 is rectangular in shape, for example, and is used to connect the terminal post of the battery cell. A second connecting part 1-2 is connected to the other side of the conductive body 1. The second connecting part 1-2 is rectangular in shape, for example, and is used to connect the tab of the battery cell. The first connecting part 1-1 and the second connecting part 1-2 can be integrally formed with the conductive body 1. The first connecting part 1-1 and the second connecting part 1-2 can be on the same plane, or they can be set on different planes as needed.

[0033] The conductive body 1 has a slot 1-3, which can be formed by processes such as stamping, cold heading, and etching. The cross-sectional shape of the slot 1-3 is, for example, rectangular or circular. By setting the slot 1-3, the cross-sectional area of ​​the conductive body 1 can be reduced. The slot 1-3 is located between the first connecting part 1-1 and the second connecting part 1-2, which is equivalent to forming a narrow flow section between the first connecting part 1-1 and the second connecting part 1-2.

[0034] The slots 1-3 are filled with conductive material 1-4, which is different from the material of the conductive body 1. Conductive material 1-4 can be a low-resistance polymer positive coefficient temperature element (PPTC) material, which includes polymer and conductive particles. Conductive material 1-4 can also be a silver-based alloy, such as Ag-SnO2.

[0035] Conductive material 1-4 fills the slots 1-3, ensuring that the current-carrying cross-sectional area of ​​the conductive body 1 remains unchanged compared to when slots 1-3 are not provided. This prevents excessive resistance due to a reduced current-carrying cross-sectional area, which would affect the cell's performance. Compared to the narrow current section design in related technologies, this cross-sectional area is larger, ensuring mechanical strength.

[0036] The melting point of conductive material 1-4 is lower than that of the material constituting conductive body 1. Thus, when the short-circuit temperature of the battery cell rises, conductive material 1-4 can melt preferentially. After melting, the current-carrying cross-sectional area at slot 1-3 is reduced, the resistance increases, the temperature at that location is raised, and then the conductive body 1 at that location is melted off, thus achieving circuit breaker protection.

[0037] In addition, the mechanical strength of conductive materials 1-4 is lower than that of conductive body 1. By retaining part of conductive body 1 and conductive materials 1-4, the mechanical performance is better than the design of the fuse part in related technologies, and the strength requirements during the use of the battery cell are met.

[0038] This adapter plate has a simple structure, is easy to manufacture, has high conductivity, high mechanical properties, and good safety.

[0039] In some embodiments, the slots 1-3 are through holes extending along the thickness direction of the conductive body 1.

[0040] like Figure 3 As shown, Figure 1 A cross-sectional diagram along the AA direction is shown. The slots 1-3 are designed as through holes extending along the thickness direction of the conductive body 1. This facilitates fabrication, and allows the conductive material 1-4 to be easily filled into the through holes. For example... Figure 1 As shown in the figure, the diagonal lines represent the current-carrying areas of the conductive body 1 at slots 1-3. Slots 1-3 are located in the middle of the current-carrying areas, and are thus surrounded by the conductive body 1, resulting in better structural stability.

[0041] In some embodiments, the current-carrying width of the through hole is a, the current-carrying width of the conductive body 1 at the through hole is c, and the through hole satisfies a / c≤65%.

[0042] like Figure 2 As shown, Figure 1 In the side view of the intermediate connector, the thicknesses of the first connecting part 1-1, the conductive body 1, and the second connecting part 1-2 are the same. The slot 1-3 is a through hole, and its depth is also the same as the thickness of the conductive body 1. Figure 1 As shown, the current-carrying width of the through hole is 'a', in mm for example, and the current-carrying width of the conductive body 1 at the through hole is 'c', in mm for example. Setting a / c ≤ 65%, for example, a / c is 65%, 60%, 50%, or 30%, etc., ensures the mechanical strength of slots 1-3 and avoids breakage due to an excessively large a / c ratio.

[0043] In some embodiments, the depth of the through hole and the thickness of the conductive body 1 are both b, the current-carrying capacity of the material of the conductive body 1 is T1, the current-carrying capacity of the conductive material 1-4 is T2, the maximum discharge power of the battery cell is Pmax, the lower voltage limit of the battery cell is Vmin, and the short-circuit current of the battery cell is Isc; the through hole satisfies a×b×T2+(c - a)×b×T1>Pmax / Vmin, and satisfies a×b×T2+(c - a)×b×T1 < Isc.

[0044] As Figure 2 shown, the thickness of the conductive body 1 is b, and the unit is, for example, mm. As Figure 3 shown, the depth of the through hole is also b.

[0045] The current-carrying capacity refers to the maximum current value that a material can withstand per unit area under the standard working conditions of the battery cell. The current-carrying capacity of the material of the conductive body 1 is T1, and the current-carrying capacity of the conductive material 1-4 is T2, and the units are, for example, both A / mm 2 . The maximum discharge power of the battery cell is Pmax, and the unit is, for example, W. The lower voltage limit of the battery cell is Vmin, and the unit is, for example, V. The short-circuit current of the battery cell is Isc, and the unit is, for example, A.

[0046] Setting a×b×T2+(c - a)×b×T1>Pmax / Vmin enables the current-carrying capacity at the slot 1-3 to meet the current-carrying requirements for normal charging and discharging of the battery cell, ensuring the normal operation of the battery cell. Setting a×b×T2+(c - a)×b×T1 < Isc enables the maximum current that the slot 1-3 can withstand to be less than the short-circuit current, ensuring that the material can be melted, thereby improving the safety of the battery cell.

[0047] In some embodiments, the slot 1-3 is a through slot extending in a direction perpendicular to the thickness of the conductive body 1, and the depth of the through slot is less than the thickness of the conductive body 1.

[0048] As Figure 4 shown, it is a schematic structural diagram of another adapter plate. The slot 1-3 is set as a through slot, and a through slot refers to a slot with openings at both ends. In this embodiment, the through slot extends in a direction perpendicular to the thickness of the conductive body 1 to the edge of the conductive body 1, enabling the conductive material 1-4 to cover the current-carrying area. As Figure 5 shown, it is Figure 4 the cross-sectional schematic diagram in the B-B direction of , and the depth of the through slot is less than the thickness of the conductive body 1, making the overall conductive body 1 at the slot 1-3 thinner, which is more convenient for disconnecting the conductive body 1 when the current is too large.

[0049] In some embodiments, the depth of the through slot is b1, the thickness of the conductive body 1 is b, and the through slot satisfies b1 / b≤50%.

[0050] As shown Figure 5 in the figure, the depth of the through slot is b1, with the unit being, for example, mm, and the thickness of the conductive body 1 is b, with the unit being, for example, mm. Set a / c ≤ 50%, such as a / c being 50%, 40%, 30% or 20%, etc., which can ensure the mechanical strength of the conductive body 1 and avoid excessive a / c ratio, resulting in stress concentration at the slot holes 1-3 and prone to fracture.

[0051] In some embodiments, the current-carrying width of the through slot is c, the current-carrying capacity of the material of the conductive body 1 is T1, the current-carrying capacity of the conductive material 1-4 is T2, the maximum discharge power of the battery cell is Pmax, the lower voltage limit of the battery cell is Vmin, and the short-circuit current of the battery cell is Isc; the through slot satisfies c×b1×T2 + c×(b - b1)×T1 > Pmax / Vmin, and satisfies c×b1×T2 + c×(b - b1)×T1 < Isc.

[0052] As shown Figure 4 in the figure, the current-carrying width of the through slot is c, with the unit being, for example, mm. Set c×b1×T2 + c×(b - b1)×T1 > Pmax / Vmin. Similarly, make the current-carrying capacity at the slot holes 1-3 meet the current-carrying requirements for normal charge and discharge of the battery cell to ensure the normal operation of the battery cell. Set c×b1×T2 + c×(b - b1)×T1 < Isc. Similarly, make the maximum current that the slot holes 1-3 can withstand less than the short-circuit current to ensure that the material can be melted and improve the safety of the battery cell.

[0053] In some embodiments, the conductive body 1 includes two of the second connecting parts 1-2, and at least one of the slot holes 1-3 is provided between each of the second connecting parts 1-2 and the first connecting part 1-1.

[0054] As shown Figure 1 in the figure, one first connecting part 1-1 is provided on one side of the conductive body 1, and two spaced second connecting parts 1-2 are provided on the other side. Each second connecting part 1-2 can be connected to one or more tab ears, with more uniform force and good current collection effect. At least one slot hole 1-3 is provided between each second connecting part 1-2 and the first connecting part 1-1. The number of slot holes 1-3 is, for example, one or more, which can ensure that both second connecting parts 1-2 can be disconnected from the first connecting part 1-1 when short-circuited, improving the safety of the battery cell.

[0055] In some embodiments of the present application, a cover plate assembly is provided, including a cover plate body 2, and the cover plate body 2 is connected with the adapter plate as described in any of the above embodiments.

[0056] As shown Figure 6The diagram shows a structural schematic of a cover plate assembly. The cover plate assembly includes a cover plate body 2, which may be, for example, an aluminum plate, but is not specifically limited thereto. An explosion-proof hole may be provided in the center of the cover plate body 2. In the event of thermal runaway of the cover plate assembly, high-temperature gas can be discharged through the explosion-proof hole to prevent an explosion.

[0057] The adapter pieces include, for example, a positive adapter piece and a negative adapter piece, which can be welded to the pole of the cover plate body 2.

[0058] The cover plate body 2 has an upper insulating component at the top and a lower insulating component at the bottom. The insulating components, such as plastic components, ensure insulation between the cover plate body 2 and the adapter plate. A limiting groove can also be provided on the cover plate body 2 to accommodate the upper insulating component. A riveting component is provided on the top surface of the upper insulating component. The electrode post passes through the lower insulating component, the cover plate body 2, and the upper insulating component in sequence and is riveted to the riveting component. The riveting component, such as a conductive block, can be electrically connected to an external circuit. The upper insulating component is located between the riveting component and the cover plate body 2, ensuring insulation between the riveting component and the cover plate body 2. The cover plate body 2 also has a liquid injection hole penetrating the cover plate body 2 for injecting electrolyte into the cover plate assembly.

[0059] The cover assembly has a simple structure, is lightweight, has high space utilization, and offers good safety.

[0060] In some embodiments of this application, a battery cell is provided, including a housing 3, the housing 3 being connected to a cover plate assembly as described in any of the above embodiments, and an electrode assembly being provided inside the housing 3.

[0061] like Figure 7 The diagram shows a schematic of a battery cell. The battery cell includes a housing 3, which is, for example, an aluminum housing, and can be welded to a cover plate assembly. Electrode assemblies are located inside the housing 3. This battery cell has a simple structure, is easy to manufacture, has high safety, and a long service life.

[0062] Battery cells can be used in electrical devices, such as vehicles, mobile phones, portable devices, laptops, ships, spacecraft, electric toys, and power tools. Vehicles can be gasoline-powered cars, natural gas-powered cars, or new energy vehicles; new energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles. Spacecraft include airplanes, rockets, space shuttles, and spacecraft. Electric toys include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys. 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.

[0063] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of this application (including the claims) is limited to these examples; within the framework of this application, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of different aspects of the embodiments of this application as described above, which are not provided in the details for the sake of brevity.

[0064] Furthermore, given that details have been set forth to describe exemplary embodiments of this application, it will be apparent to those skilled in the art that embodiments of this application may be practiced without these details or with variations thereof. Therefore, these descriptions should be considered illustrative rather than restrictive.

[0065] Although this application has been described in conjunction with embodiments thereof, many substitutions, modifications and variations of these embodiments will be apparent to those skilled in the art from the foregoing description.

[0066] The embodiments of this application are intended to cover all such substitutions, modifications, and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the embodiments of this application should be included within the protection scope of this application.

Claims

1. An adapter plate, characterized in that, include: A conductive body includes a first connecting part and a second connecting part, wherein the first connecting part is used to connect to the terminal post of the battery cell, and the second connecting part is used to connect to the tab of the battery cell; A slot is disposed on the conductive body, located between the first connecting portion and the second connecting portion, and the depth of the slot is less than or equal to the thickness of the conductive body; the slot is filled with a conductive material, and the melting point of the conductive material is less than the melting point of the material constituting the conductive body.

2. The adapter plate according to claim 1, characterized in that, The slot is a through hole that extends along the thickness direction of the conductive body.

3. The adapter plate according to claim 2, characterized in that, The through-hole has a current-carrying width of a, the conductive body has a current-carrying width of c at the through-hole, and the through-hole satisfies a / c≤65%.

4. The adapter plate according to claim 3, characterized in that, The depth of the through-hole and the thickness of the conductive body are both b. The current carrying capacity of the conductive body material is T1, the current carrying capacity of the conductive material is T2, the maximum discharge power of the battery cell is Pmax, the lower voltage limit of the battery cell is Vmin, and the short-circuit current of the battery cell is Isc. The through-hole satisfies a×b×T2+(ca)×b×T1>Pmax / Vmin, and also satisfies a×b×T2+(ca)×b×T1 <Isc。 5. The adapter plate according to claim 1, characterized in that, The slot is a through-slot extending in a direction perpendicular to the thickness of the conductive body, and the depth of the through-slot is less than the thickness of the conductive body.

6. The adapter plate according to claim 5, characterized in that, The depth of the through groove is b1, the thickness of the conductive body is b, and the through groove satisfies b1 / b≤50%.

7. The adapter plate according to claim 6, characterized in that, The through-slot has a current-carrying width of c, the conductive body material has a current-carrying capacity of T1, the conductive material has a current-carrying capacity of T2, the battery cell has a maximum discharge power of Pmax, the battery cell has a lower voltage limit of Vmin, and the battery cell has a short-circuit current of Isc; the through-slot satisfies c×b1×T2 + c×(b-b1)×T1 > Pmax / Vmin, and also satisfies c×b1×T2 + c×(b-b1)×T1 <Isc。 8. The adapter plate according to claim 1, characterized in that, The conductive body includes two second connecting portions, and each second connecting portion and the first connecting portion are provided with at least one slot.

9. A cover plate assembly, characterized in that, It includes a cover plate body, wherein the cover plate body is connected to an adapter piece as described in any one of claims 1-8.

10. A battery cell, characterized in that, It includes a housing, the housing being connected to the cover plate assembly as described in claim 9, and the interior of the housing being provided with an electrode assembly.

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