Pole assembly, cover plate assembly and battery cell

Abstract

The utility model provides a pole assembly, a cover plate assembly and a battery cell, the pole assembly comprises a bottom plate and a pole body mounted on the bottom plate, the bottom plate comprises a bottom plate body, a cover plate, a first electrode and a second electrode, the two connecting parts are located on the two sides of the bottom plate body in the length direction respectively, and the connecting parts are arranged in the width direction of the bottom plate body; the thinning area is arranged on the connecting part and used for being connected with a tab of an electrode assembly, the thickness of the thinning area is smaller than that of the bottom plate body, and the width of the thinning area is larger than or equal to that of the tab. The pole assembly, the cover plate assembly and the battery cell provided by the utility model are simple in structure, convenient to manufacture, light in weight, high in space utilization rate and good in safety.

Description

Technical Field

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

[0002] With the continuous development of the new energy industry, higher requirements are being placed on batteries. As an important component of the battery structure, the electrode assembly has also undergone several developments. The electrode assembly is mainly composed of the electrode body and the base plate. The existing electrode assembly is relatively heavy and has low space utilization. Therefore, there is an urgent need for an electrode assembly with optimized structure. Utility Model Content

[0003] In view of this, the purpose of this application is to provide a terminal assembly, 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 electrode assembly, including a base plate and an electrode body mounted on the base plate. The base plate includes: a base plate body; two connecting portions located on both sides of the base plate body along its length direction, the connecting portions being disposed along the width direction of the base plate body; and a thinning region disposed on the connecting portions for connecting tabs of the electrode assembly, the thickness of the thinning region being less than the thickness of the base plate body, and the width of the thinning region being greater than or equal to the width of the tabs.

[0005] Furthermore, the base plate is a metal plate, and the thinning zone is formed by cold forging the metal plate.

[0006] Furthermore, the sum of the thickness of the thinned region and the thickness of the tab is less than or equal to the thickness of the base plate body.

[0007] Furthermore, the base plate body has through holes at both ends along the length direction, and the through holes and the connecting parts are correspondingly spaced apart; the distance between the connecting part and the corner of the base plate and the through hole is the fusion gap, which is less than the length of the connecting part.

[0008] Furthermore, the orthographic projection of the thinning zone on the base plate covers the connecting portion and part of the base plate body, and the length of the thinning zone located on the base plate body is greater than the length of the connecting portion.

[0009] Furthermore, an opening groove is provided at the corner where the connecting part connects to the base plate, and the opening groove is provided along the width direction.

[0010] Furthermore, the width of the opening groove is less than the distance between the connecting part and the through hole, and the width of the thinning zone is equal to the sum of the width of the opening groove and the width of the connecting part.

[0011] Furthermore, the distance between the opening groove and the through hole is L1, the thickness of the base plate body is D1, the length of the connecting part is L2, and the thickness of the thinning area is D2, satisfying L1*D1≤L2*D2.

[0012] A second aspect of this application provides a cover plate assembly, including a cover plate body and a pole assembly as described in the first aspect above, the pole assembly penetrating the cover plate body.

[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 electrode post assembly, cover plate assembly, and battery cell provided in this application include an electrode post assembly comprising a base plate and electrode posts mounted on the base plate. The base plate includes: a base plate body; two connecting portions located on both sides of the base plate body along its length, with the connecting portions also arranged along the width direction of the base plate body; and a thinning region disposed on the connecting portions for connecting the electrode tabs of the electrode assembly. The thickness of the thinning region is less than the thickness of the base plate body, and the width of the thinning region is greater than or equal to the width of the electrode tabs. Through the cooperation of the thinning region and the electrode tabs, the weight of the electrode post assembly is reduced while ensuring electrical connection, and the space utilization rate of the electrode post assembly within the battery cell is also improved. This electrode post assembly, cover plate assembly, and battery cell have a simple structure, are easy to manufacture, are lightweight, have high space utilization, and offer 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 the first type of pole assembly in the embodiments of this application;

[0017] Figure 2 This is a top view of the second type of pole assembly in the embodiments of this application;

[0018] Figure 3 This is a top view of the third type of pole assembly in the embodiments of this application;

[0019] Figure 4 for Figure 3 A three-dimensional structural diagram of the center pole assembly.

[0020] Reference numerals: 1. Base plate; 1-1. Base plate body; 1-2. Connecting part; 1-3. Thinning area; 1-4. Through hole; 1-5. Opening groove; 2. Electrode column; 3. Electrode tab. Detailed Implementation

[0021] 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.

[0022] 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.

[0023] With the continuous development of the new energy industry, higher requirements are being placed on batteries. As an important component of the battery structure, the electrode assembly has also undergone several developments. The electrode assembly is mainly composed of the electrode body and the base plate. The existing electrode assembly is relatively heavy and has low space utilization. Therefore, there is an urgent need for an electrode assembly with optimized structure.

[0024] The current welding method for electrode components and cover plate components in lithium-ion batteries has eliminated the positive and negative electrode connecting pieces and ultrasonic welding protective pieces. Instead, the electrode tabs of the electrode components are directly laser-welded to the base plate of the electrode post component. Therefore, the size of the base plate needs to be made larger, which results in a larger base plate weight, especially on the negative electrode side, since the base plate is made of copper, which has a high copper density and therefore a greater weight. In addition, the base plate is thicker after being connected to the tabs, and the flatness of the base plate is relatively low, which also reduces the space utilization rate inside the cell.

[0025] The following describes specific embodiments in conjunction with the appendix. Figures 1 to 4 The technical solution of this application will be further described in detail.

[0026] In some embodiments of this application, a pole post assembly is provided, such as... Figure 1As shown, the device includes a base plate 1 and an electrode post 2 mounted on the base plate 1. The base plate 1 includes: a base plate body 1-1; two connecting parts 1-2, located on both sides of the base plate body 1-1 along its length, and the connecting parts 1-2 are both arranged along the width direction of the base plate body 1-1; and a thinning region 1-3, disposed on the connecting parts 1-2, for connecting the electrode tabs 3 of the electrode assembly. The thickness of the thinning region 1-3 is less than the thickness of the base plate body 1-1, and the width of the thinning region 1-3 is greater than or equal to the width of the electrode tabs 3.

[0027] like Figure 1 As shown, the pole assembly includes a base plate 1 and a pole body 2. The base plate 1 is, for example, a metal plate, and the pole body 2 is, for example, a metal pole, which can be fixed to the middle of the base plate 1 by fasteners.

[0028] The base plate 1 includes a base plate body 1-1 and two connecting parts 1-2. In the figure, the L direction is the length direction of the base plate body 1-1, the W direction is the width direction of the base plate body 1-1, and the dotted line in the figure is the dividing line between the connecting parts 1-2 and the base plate body 1-1. The base plate body 1-1 is, for example, a rectangular structure. The two connecting parts 1-2 are used to connect the electrode tabs 3. The electrode tabs 3 can be folded onto the connecting parts 1-2 for welding connection. Compared with the design of one electrode tab 3, the total thickness of the electrode tab 3 and the connecting parts 1-2 can be reduced, thereby improving the space utilization rate.

[0029] A thinning zone 1-3 is provided on the connecting part 1-2. It can be made by cold heading or grinding processes. The thickness of the thinning zone 1-3 is less than the thickness of the base plate body 1-1, and the width is greater than the width of the tab 3. In this way, the tab 3 can be welded within the thinning zone 1-3. While meeting the electrical connection requirements, it not only reduces the weight of the pole assembly, but also reduces the total thickness of the connecting part 1-2 and the tab 3, thereby improving the space utilization rate of the pole assembly within the cell.

[0030] The thinning area 1-3 can be set on the upper surface of the connecting part 1-2, so that the electrode tab 3 can be folded onto the thinning area 1-3 for connection, making the fit more secure; the thinning area 1-3 can also be set on the lower surface of the connecting part 1-2, and directly welded to the electrode tab 3, which is closer to the electrode assembly; the thinning area 1-3 can be set on the inner side of the connecting part 1-2, so as not to increase the overall length of the base plate 1; the thinning area 1-3 can partially cover the connecting part 1-2, just enough to meet the space requirements for accommodating the electrode tab 3; the thinning area 1-3 can also completely cover the connecting part 1-2, or even partially cover the base plate body 1-1, which can further reduce the weight of the base plate 1.

[0031] The pole assembly has a simple structure, is easy to manufacture, is lightweight, has high space utilization, and is safe.

[0032] In some embodiments, the base plate 1 is a metal plate, and the thinning regions 1-3 are formed by cold forging the metal plate.

[0033] By using the cold heading process, the thickness of the thinning zone 1-3 is reduced while the length of the connecting part 1-2 is increased, thereby increasing the heat dissipation area and improving heat dissipation capacity.

[0034] In some embodiments, the sum of the thickness of the thinning region 1-3 and the thickness of the tab 3 is less than or equal to the thickness of the base plate body 1-1.

[0035] A thinning zone 1-3 can be connected to one or more tabs 3. When connecting multiple tabs 3, the thickness of the tab 3 is, for example, the thickness of a single tab * the number of tab layers * n, which is not limited in specific terms. The sum of the thickness of the thinning zone 1-3 and the total thickness of the tabs 3 is set to be less than or equal to the thickness of the base plate body 1-1. The purpose is to ensure that the tabs 3 can be completely buried in the base plate 1, ensuring the flatness of the base plate 1 and avoiding affecting the assembly of the pole assembly and the cover plate body.

[0036] In some embodiments, such as Figure 1 As shown, the base plate body 1-1 has through holes 1-4 at both ends along the length direction, and the through holes 1-4 and the connecting part 1-2 are arranged at intervals. The distance between the connecting part 1-2 and the corner of the base plate 1 and the through hole 1-4 is the fusion gap, which is less than the length of the connecting part 1-2.

[0037] like Figure 1 As shown, the base plate body 1-1 is also provided with a through hole 1-4. The through hole 1-4 is, for example, a square hole, and the specific design is not limited. The through hole 1-4 can reduce the cross-sectional area of ​​the base plate body 1-1. In this way, when a short circuit occurs, the current at that point can be increased, the heat can be increased, and the base plate body 1-1 can be melted to prevent the battery cell from short-circuiting.

[0038] like Figure 1 As shown, L0 is the distance between the connection corner of the connecting part 1-2 and the base plate 1 and the through hole 1-4, i.e. the fusion gap, and L2 is the length of the connecting part 1-2. Setting L0 < L2 ensures that the fusion occurs between the through hole 1-4 and the connection corner, thus improving safety.

[0039] In some embodiments, such as Figure 2 As shown, the orthographic projection of the thinning region 1-3 on the base plate 1 covers the connecting part 1-2 and part of the base plate body 1-1, and the length of the thinning region 1-3 located on the base plate body 1-1 is greater than the length of the connecting part 1-2.

[0040] like Figure 2As shown in the figure, the thick solid line is the fuse line of the base plate 1. The cross-sectional width is the shortest at this point along the path from the connecting part 1-2 to the pole body 2, so it is easier for the fuse to break at this point when a short circuit occurs.

[0041] The entire connecting part 1-2 is thinned, and the thinned area 1-3 also partially covers the base plate body 1-1, so that the width of the thinned area 1-3 is greater than the width of the connecting part 1-2, and the length of the thinned area 1-3 located on the base plate body 1-1 is greater than the length of the connecting part 1-2. In this way, the thinned area 1-3 can at least partially cover the fuse line, further reducing the cross-sectional area at the fuse line, which is more conducive to fusing and avoiding short circuit of the battery cell.

[0042] In some embodiments, such as Figure 3 and Figure 4 As shown, an opening groove 1-5 is provided at the corner where the connecting part 1-2 connects to the base plate 1, and the opening groove 1-5 is arranged along the width direction.

[0043] like Figure 4 As shown, an opening groove 1-5 is provided at the corner where the connecting part 1-2 connects to the base plate 1. The opening groove 1-5 is, for example, a rectangular groove, which can provide clearance space. In this way, the electrode 3 can pass through the opening groove 1-5 and connect with the thinning area 1-3, which is convenient for connection. The opening groove 1-5 can also further reduce the cross-sectional area of ​​the base plate body 1-1, making it easier for the fuse to melt at the fuse line when a short circuit occurs.

[0044] In some embodiments, such as Figure 3 As shown, the width of the opening groove 1-5 is less than the distance between the connecting part 1-2 and the through hole 1-4, and the width of the thinning area 1-3 is equal to the sum of the width of the opening groove 1-5 and the width of the connecting part 1-2.

[0045] like Figure 3 As shown, the width of the opening groove 1-5 is less than the distance between the connecting part 1-2 and the through hole 1-4, ensuring the structural strength of the base plate 1. The width of the thinning area 1-3 is equal to the sum of the width of the opening groove 1-5 and the width of the connecting part 1-2, increasing the mating area between the thinning area 1-3 and the tab 3, which facilitates manufacturing.

[0046] In some embodiments, such as Figure 3 As shown, the distance between the opening groove 1-5 and the through hole 1-4 is L1, the thickness of the base plate body 1-1 is D1, the length of the connecting part 1-2 is L2, and the thickness of the thinning area 1-3 is D2, satisfying L1*D1≤L2*D2.

[0047] like Figure 3As shown, L1 is the distance between the opening slot 1-5 and the through hole 1-4, which is the shortest cross-sectional width along the path from the connecting part 1-2 to the pole body 2. L2 is the length of the connecting part 1-2, and L3 is the length of the opening slot 1-5. The thickness of the base plate body 1-1 without the thinning area 1-3 is D1, and the thickness of the thinning area 1-3 is D2. By adjusting the length of L3, L1*D1≤L2*D2 can be made, that is, the cross-sectional area between the opening slot 1-5 and the through hole 1-4 should be smaller than the cross-sectional area of ​​the connecting part 1-2. This ensures that when a short circuit occurs, the fuse will blow between the opening slot 1-5 and the through hole 1-4, improving safety and preventing the battery cell from catching fire and exploding due to a short circuit.

[0048] In some embodiments of this application, a cover plate assembly is provided, including a cover plate body and a pole post assembly as described in any of the above embodiments, the pole post assembly penetrating the cover plate body.

[0049] The cover plate body is, for example, an aluminum plate, and there is no specific limitation. The cover plate body can be provided with an explosion-proof hole in the middle. In the event of thermal runaway of the cover plate assembly, high-temperature gas can be discharged through the explosion-proof hole to avoid an explosion.

[0050] The terminal assembly includes, for example, a positive terminal assembly and a negative terminal assembly. One end of the terminal assembly is located below the cover plate body and is used for electrical connection with the electrode assembly inside the cell housing; the other end of the terminal assembly is located above the cover plate body and is used for electrical connection with the external circuit of the cover plate assembly.

[0051] The cover plate body 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 and the electrode assembly. A limiting groove can also be provided on the cover plate body to accommodate the upper insulating component. A riveting component is provided on the top surface of the upper insulating component. The electrode assembly passes through the lower insulating component, the cover plate body, 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, ensuring insulation between the riveting component and the cover plate body. The cover plate body also has a liquid injection hole penetrating the cover plate body for injecting electrolyte into the cover plate assembly.

[0052] The cover assembly has a simple structure, is lightweight, has high space utilization, and offers good safety.

[0053] In some embodiments of this application, a battery cell is provided, including a housing, the housing being connected to a cover plate assembly as described in any of the above embodiments, and having an electrode assembly disposed inside.

[0054] The casing, for example, is made of aluminum and can be welded to the cover plate assembly. This battery cell has a simple structure, is easy to manufacture, offers high safety, and has a long service life.

[0055] 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.

[0056] 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.

[0057] 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.

[0058] 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.

[0059] 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. A pole assembly, characterized in that, Includes a base plate and an electrode post mounted on the base plate, the base plate comprising: base plate body; Two connecting parts are located on both sides of the base plate body along the length direction, and the connecting parts are both arranged along the width direction of the base plate body; A thinning region is provided on the connecting part for connecting the tabs of the electrode assembly. The thickness of the thinning region is less than the thickness of the base plate body, and the width of the thinning region is greater than or equal to the width of the tab.

2. The pole assembly according to claim 1, characterized in that, The base plate is a metal plate, and the thinning zone is formed by cold forging the metal plate.

3. The pole assembly according to claim 1, characterized in that, The sum of the thickness of the thinning zone and the thickness of the tab is less than or equal to the thickness of the base plate body.

4. The pole assembly according to claim 1, characterized in that, The base plate body has through holes at both ends along the length direction, and the through holes and the connecting parts are arranged at intervals. The distance between the connecting part and the corner of the base plate and the through hole is the fusion gap, which is less than the length of the connecting part.

5. The pole assembly according to claim 4, characterized in that, The orthographic projection of the thinning zone onto the base plate covers the connecting portion and part of the base plate body, and the length of the thinning zone located on the base plate body is greater than the length of the connecting portion.

6. The pole assembly according to claim 4, characterized in that, An opening groove is provided at the corner where the connecting part connects to the base plate, and the opening groove is arranged along the width direction.

7. The pole assembly according to claim 6, characterized in that, The width of the opening groove is less than the distance between the connecting part and the through hole, and the width of the thinning zone is equal to the sum of the width of the opening groove and the width of the connecting part.

8. The pole assembly according to claim 6, characterized in that, The distance between the opening groove and the through hole is L1, the thickness of the base plate body is D1, the length of the connecting part is L2, and the thickness of the thinning area is D2, satisfying L1*D1≤L2*D2.

9. A cover plate assembly, characterized in that, It includes a cover plate body and a pole assembly as described in any one of claims 1-8, wherein the pole assembly penetrates the cover plate body.

10. A battery cell, characterized in that, It includes a housing, the housing being connected to the cover plate assembly of claim 9, and having an electrode assembly inside.

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