A battery top cover aluminum plate, a battery top cover structure, and a battery.

Abstract

This invention provides a battery top cover aluminum plate, a battery top cover structure, and a battery. The aluminum plate (104) has an aluminum substrate in the middle section for setting the flange structure (1041) with a thickness unequal to that of the aluminum substrate on the outer periphery of the middle section, and a gap exists between the flange structure (1041) and the aluminum substrate on the outer periphery of the middle section, forming a groove. The depth (L3) of the groove ranges from 0 to L3 to 2 mm. The distance L2 between the flange structure (1041) and the main body of the aluminum plate ranges from 0 to L2 to 4 mm. The aluminum plate ensures the strength of the flange and reduces stress concentration at the bending point caused by bending the flange, thus preventing cracking.

Description

Technical Field

[0001] This invention belongs to the field of lithium battery cell structure design, specifically relating to a battery top cover structure, assembly method, and battery. Background Technology

[0002] The statements in this section are merely background information related to the present invention and do not necessarily constitute prior art.

[0003] Cylindrical lithium battery top covers are mostly traditional riveted structures, which have complex assembly processes, a large number of parts, high costs, and large space occupancy rates, affecting the energy density and capacity of lithium batteries.

[0004] The existing lithium battery cover structure includes a positive electrode post, a conductive sheet, a top cover sheet, and a plastic cover plate. The conductive sheet is connected to the positive electrode post, the positive electrode post is insulated from the top cover sheet, and the plastic cover plate is connected to the top cover sheet.

[0005] The aforementioned cover plate structure lacks a relevant limiting mechanism, thus failing to guarantee the structural stability of the top cover or cover plate.

[0006] In addition, when bending aluminum sheets, the sheets often crack after bending due to their own rigidity, which increases the defect rate of the products. Such bent aluminum sheets can also bring considerable hidden dangers to subsequent products and affect the performance of the final product.

[0007] Therefore, the design of the aluminum plate in the cover plate structure is very important, and it is necessary to avoid stress concentration and cracking problems when the aluminum plate is bent. Summary of the Invention

[0008] To address the aforementioned problems, this invention proposes a battery top cover aluminum plate, a battery top cover structure, and a battery. The aluminum plate features an unequal thickness design at the bending points, which further improves the bending performance of the top cover aluminum plate and avoids stress concentration and cracking during bending.

[0009] This invention optimizes the mechanical performance of the top cover by limiting its vertical and circumferential movement through structural design, thus ensuring the structural stability of the top cover.

[0010] According to some embodiments, the present invention adopts the following technical solution:

[0011] In the first aspect, a battery top cover aluminum plate is disclosed, wherein the aluminum plate substrate in the middle of the aluminum plate (104) for setting the flange structure (1041) has different thicknesses from the aluminum plate substrate in the middle periphery, and there is a gap between the flange structure (1041) and the aluminum plate substrate in the middle periphery to form a groove.

[0012] The depth (L3) of the groove is in the range of 0 < L3 ≤ 2 mm; the distance L2 between the flange structure (1041) and the main body of the aluminum plate is in the range of 0 < L2 ≤ 4 mm.

[0013] As a further technical solution, the flange structure (1041) is formed by stamping and bending the aluminum plate substrate, and is an integral structure with the aluminum plate (104).

[0014] As a further preferred technical solution, the flange structure (1041) is also uniformly distributed with groove structures (1042), which surround the flange structure (1041).

[0015] As a further preferred technical solution, the thickness (D2) of the flange structure (1041) is in the range of 0.5mm≤D2≤2.5mm.

[0016] As a further preferred technical solution, the relationship between the thickness (D2) of the flange structure (1041) and the thickness D1 of the aluminum plate substrate in the middle periphery is: 0.2≤D2 / D1<1.

[0017] In a second aspect, a battery top cover structure is disclosed, comprising: the battery top cover aluminum plate (104) described in the first aspect.

[0018] As a further preferred technical solution, the battery top cover structure also includes a negative electrode post (101), an injection-molded upper plastic (102), fluororubber (103), and a lower plastic (105).

[0019] The negative electrode post (101) includes a disk structure (1012) and a cylinder disposed on the disk structure (1012). A groove structure (1011) is provided on the cylindrical surface (1013) on the outer side of the cylinder. The groove structure (1011) restricts the movement of the negative electrode post (101) after being dissolved into the injection-molded plastic (102).

[0020] As a further technical solution, the groove structure (1011) is multiple and is evenly or unevenly arranged on the cylindrical surface (1013) of the negative electrode post (101).

[0021] As a further preferred technical solution, the depth (H1) of the groove structure (1011) is in the range of 0 < H1 ≤ 2 mm, and the height (L1) of the groove structure (1011) is in the range of 0 < L1 ≤ 4 mm.

[0022] As a further preferred technical solution, the cut surface of the groove structure 1011 on the cylindrical surface 1013 is a plane, a concave surface, or a triangle.

[0023] As a further technical solution, the lower plastic (105) and fluororubber (103) are respectively sleeved on the negative electrode post (101), the fluororubber (103) is pressed on the upper surface of the disc structure (1012) excluding the mounting cylinder, and the aluminum plate (104) is used to press on the fluororubber (103).

[0024] Thirdly, a method for assembling a battery top cover structure is disclosed, including:

[0025] The lower plastic (105) and fluororubber (103) are fitted onto the negative electrode post (101);

[0026] Then, the aluminum plate (104) is pressed onto the fluororubber (103) and squeezed through the mold to ensure the compression of the fluororubber (103). At the same time, the assembled components are injected with plastic (102) into the mold.

[0027] When the injection molding plastic (102) is injected into the component, the slot structure (1041) of the aluminum plate (104) and the grooving structure (1011) of the negative electrode post (101) respectively limit the aluminum plate (104) and the negative electrode post (101) radially and axially.

[0028] Fourthly, a battery is disclosed, including a battery top cover structure, an aluminum shell (2), a negative electrode current collector (3), a core (4), and a positive electrode current collector (5);

[0029] The battery top cover structure includes a negative electrode top cover (1), which is electrically connected to a negative electrode current collector (3). Both the negative electrode current collector (3) and the positive electrode current collector (5) are electrically connected to the core (4), and the positive electrode current collector (5) is also electrically connected to the aluminum shell (2).

[0030] As a further technical solution, the aluminum plate (104) of the negative electrode top cover (1) is electrically connected to the aluminum shell (2).

[0031] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0032] 1. The aluminum plate substrate in the middle of the aluminum plate (104) of the present invention, which is used to set the flange structure (1041), has a different thickness from the aluminum plate substrate in the outer part of the middle. The thickness of the aluminum plate substrate of the flange structure (1041) is less than that of the aluminum plate substrate in the outer part of the middle. This can ensure the strength of the flange and reduce the stress concentration at the bending point caused by bending and flange, thus avoiding cracking.

[0033] 2. There is a gap between the flange structure (1041) and the aluminum plate substrate in the middle periphery of the present invention, forming a groove. The depth (L3) of the groove is in the range of 0 < L3 ≤ 2 mm. The distance L2 between the flange structure (1041) and the main body of the aluminum plate is in the range of 0 < L2 ≤ 4 mm. The groove can avoid interference between the flange structure and the main structure when bending. At the same time, it leaves more contact area for the injection molding of plastic (102) and ensures that the structure is more reliable.

[0034] Advantages of additional aspects of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.

[0035] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0036] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0037] Figure 1(a)-Figure 1(d) The following are three-dimensional perspective views, top views, AA cross-sectional views, and enlarged views of the aluminum plate structure according to embodiments of the present invention;

[0038] Figure 1(e)-Figure 1(g) The following are three-dimensional perspective views, sectional views, and enlarged views of the aluminum plate structure before bending in an embodiment of the present invention;

[0039] Figure 2(a)-Figure 2(b) This is a cross-sectional view and exploded structural diagram of the top cover of the negative electrode according to an embodiment of the present invention;

[0040] Figures 3(a)-3(c) This is a schematic diagram, top view, and AA cross-sectional view of the three-dimensional structure of the negative electrode post according to an embodiment of the present invention;

[0041] Figure 3(d) is a schematic diagram of another structure of the negative electrode post in an embodiment of the present invention;

[0042] Figure 4 This is a schematic diagram of the overall structure of the cylindrical lithium battery according to an embodiment of the present invention;

[0043] In the diagram, 1 is the negative electrode top cover; 2 is the aluminum shell; 3 is the negative electrode current collector; 4 is the winding core; and 5 is the positive electrode current collector.

[0044] 101 Negative electrode post; 102 Upper injection molded plastic; 103 Fluororubber; 104 Aluminum plate; 105 Lower plastic;

[0045] 1011 Grooved structure; 1012 Disc structure; 1013 Cylindrical surface; 1041 Flanged structure; 1042 Slotted structure;

[0046] D2: Thickness of the flange structure; L2: Distance between the flange structure and the main body of the aluminum plate; L3: Depth of the groove; D1: Thickness of the aluminum plate;

[0047] H1: Depth of the grooving structure; L1: Height of the grooving structure. Detailed Implementation

[0048] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0049] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0050] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0051] Example 1:

[0052] See appendix Figure 1(a)-Figure 1(d) As shown, this embodiment discloses a battery top cover aluminum plate, including a flange structure (1041). The aluminum plate substrate in the middle of the aluminum plate (104) for setting the flange structure (1041) has different thicknesses from the aluminum plate substrate in the middle periphery, and there is a gap between the flange structure (1041) and the aluminum plate substrate in the middle periphery to form a groove.

[0053] The depth (L3) of the above-mentioned groove is in the range of 0 < L3 ≤ 2 mm; the distance L2 between the flange structure (1041) and the main body of the aluminum plate is in the range of 0 < L2 ≤ 4 mm.

[0054] The flange structure (1041) is formed by stamping and bending the aluminum plate substrate, and is an integral structure with the aluminum plate (104).

[0055] In this embodiment, a slot structure (1042) is also included, which surrounds the flange structure (1041). The slot structure (1042) can be circular, rectangular, or oblong, etc.

[0056] See attached diagram for the structure of the aluminum substrate before bending. Figure 1(e)-Figure 1(g)As shown, the aluminum plate substrate in the middle of the aluminum plate (104) used to set the flange structure (1041) has different thicknesses from the aluminum plate substrate in the outer part of the middle part, and there is a gap between the flange structure (1041) and the aluminum plate substrate in the outer part of the middle part, forming a groove, which is convenient for bending.

[0057] Referring again to Figure 1(e), the thickness of the aluminum substrate in the middle for setting the flange structure (1041) is lower than the thickness of the aluminum substrate in the outer middle.

[0058] Since the thinner the metal part is at the bend, the easier it is to bend and the less likely it is to cause stress concentration, thus effectively avoiding the problem of bending cracks; however, due to the structural strength requirements, the aluminum plate needs to maintain a certain thickness. Therefore, in this embodiment, the thickness of the flange structure (1041) is selected as 0.5≤D1≤2.5mm, which can ensure the strength of the flange and reduce the stress concentration at the bend caused by bending the flange, thus avoiding cracking. The preferred values ​​are 1.0mm, 1.5mm, and 2.0mm.

[0059] Based on the material thickness of the entire structure, the preferred relationship between the thickness (D2) of the flange structure (1041) and the thickness (D1) of the aluminum plate substrate in the middle periphery is: 0.2≤D2 / D1<1.

[0060] More specifically, the distance between the flange and the main body of the aluminum plate is 0 < L2 ≤ 4mm, with preferred values ​​of 1mm, 1.5mm, 2.0mm, and 3mm. (L3) is the depth of the groove, with a range of 0 < L3 ≤ 2mm, and preferred values ​​of 0.5mm and 1.0mm. This avoids interference between the flange and the main structure during bending, and also provides more contact area for the injection-molded plastic 102, ensuring a more robust structure.

[0061] Example 2:

[0062] In this embodiment, a lithium battery top cover structure is used as an example, but this does not mean that the battery top cover structure provided by the present invention is only applicable to lithium batteries. It can also be applied to other types of battery structures depending on the type of battery installed.

[0063] In this embodiment, a battery top cover structure is disclosed, including: a negative electrode top cover (1), the negative electrode top cover (1) being composed of a negative electrode post (101), an injection-molded upper plastic (102), fluororubber (103), an aluminum plate (104), and a lower plastic (105), as shown below. Figure 2(a)-Figure 2(b) As shown.

[0064] The negative electrode post (101) includes a disk structure (1012) and a cylinder disposed on the disk structure (1012). A groove structure (1011) is formed on the cylindrical surface (1013) on the outer side of the cylinder, such as... Figures 3(a)-3(b)As shown.

[0065] In one embodiment, four slotted structures (1011) are evenly arranged on the cylindrical surface (1013) of the negative terminal post (101).

[0066] Figure 3(d) is a schematic diagram of another embodiment of the negative electrode post, in which there are two slotted structures (1011). The number of slotted structures (1011) can be adjusted according to actual needs and is not limited here.

[0067] The aforementioned groove structure (1011) is opened on the cylinder of the negative electrode post (101), and the cut surface left on the cylindrical surface (1013) after opening is a plane, a concave surface, etc.

[0068] When the injection-molded plastic (102) is incorporated into the groove structure (1011), it can greatly enhance the structural strength of the top cover and restrict the radial and axial movement, especially the rotational movement, of the negative electrode post (101).

[0069] In one embodiment, the depth (H1) of the grooving structure (1011) satisfies: 0 < H1 ≤ 2 mm, and its height (L1) satisfies: 0 < L1 ≤ 4 mm, as shown in Figure 3(c).

[0070] The aforementioned disc structure (1012) is mainly used to cooperate with fluororubber (103) to achieve the sealing of the entire structure by compressing the fluororubber (103).

[0071] In this embodiment, due to the presence of the slot structure (1042) of the aluminum plate (104) and the groove structure (1011) of the negative electrode post (101), when the injection molding plastic (102) is injected into the component, the aluminum plate (104) and the negative electrode post (101) are respectively limited radially and axially. This prevents the aluminum plate (104) and the negative electrode post (101) from rotating relative to each other in the axial direction, and also prevents the aluminum plate (104) and the negative electrode post (101) from moving relative to each other in the vertical direction, thereby ensuring the overall structural stability.

[0072] In this embodiment, the aluminum plate (104) and the aluminum shell (2) are laser welded together, achieving both electrical and structural connection. Structurally, this integrates the aluminum plate (104) and the aluminum shell (2) and seals the battery.

[0073] Since the negative electrode post (101) is not fixed during the sealing process, in this embodiment, the aluminum plate (104) is pressed on the fluororubber (103) and squeezed by the mold to fit the negative electrode post (101), which can prevent the negative electrode post (101) from shifting in the horizontal direction.

[0074] Since the vertical displacement and torsion of the negative electrode post (101) are not restricted, in this embodiment, by setting the flange structure (1041) and the slot structure (1042) on the aluminum plate (104), the injection-molded plastic (102) can be very well fixed. At the same time, by fixing the injection-molded plastic (102) to the negative electrode post (101) with the slotted structure (1011), the vertical movement and rotational movement of the negative electrode post (101) can be prevented. It can be considered that in this embodiment of the invention, the injection-molded plastic (102) is firmly fixed by the flange structure (1041) and the slot structure (1042) on the aluminum plate (104), and at the same time, the slotted structure (1011) on the negative electrode post (101) is firmly fixed by the injection-molded plastic (102), preventing the negative electrode post (101) from vertical displacement and rotational displacement.

[0075] In one embodiment, a method for assembling a battery top cover structure is also disclosed, comprising:

[0076] The lower plastic (105) and fluororubber (103) are fitted onto the negative electrode post (101);

[0077] Then, the aluminum plate (104) is pressed onto the fluororubber (103) and squeezed through the mold to ensure the compression of the fluororubber (103). At the same time, the assembled components are injected with plastic (102) into the mold.

[0078] When the injection-molded plastic (102) is injected into the component, the slot structure (1041) of the aluminum plate (104) and the groove structure (1011) of the negative electrode post (101) respectively limit the aluminum plate (104) and the negative electrode post (101) radially and axially. The structural strength is achieved after the injection-molded plastic (102) cools down.

[0079] This embodiment optimizes the structure of the negative electrode post (101) and the aluminum plate (104) to ensure the structural strength of the battery cell top cover. This is mainly reflected in the fact that the negative electrode post (101) is provided with a groove structure (1011), the aluminum plate (104) is provided with a flange structure (1041) and a slot structure (1042), and then the injection molding process is used to completely fix and lock the three together, thereby achieving the sealing, insulation and structural strength of the structure.

[0080] The top cover structure of this invention simplifies the top cover structure, reduces the production cost of the top cover, and improves the space utilization of the lithium battery. At the same time, it also optimizes the mechanical performance of the top cover. The structural design limits the top cover in the vertical and circumferential directions, ensuring the structural stability of the top cover.

[0081] In this invention, due to the presence of the slot structure (1042) of the aluminum plate (104) and the groove structure (1011) of the negative electrode post (101), when the injection molding plastic (102) is injected into the component, the aluminum plate (104) and the negative electrode post (101) are respectively limited radially and axially. This can prevent the aluminum plate (104) and the negative electrode post (101) from rotating relative to each other in the axial direction, and can also prevent the aluminum plate (104) and the negative electrode post (101) from moving relative to each other in the vertical direction, thereby ensuring the overall structural stability.

[0082] During the assembly of the negative electrode top cover of the present invention, the lower plastic and fluororubber are sleeved on the negative electrode post, and then the aluminum plate is pressed on the fluororubber. The compression of the fluororubber is ensured by extrusion through a mold. At the same time, the upper plastic is injected into the mold. The negative electrode post has a groove structure, the main function of which is to greatly enhance the structural strength of the top cover after the upper plastic is fused into the groove structure, and to restrict the radial and axial movement of the negative electrode post. The structural strength is achieved after the upper plastic cools down.

[0083] Example 3:

[0084] Based on the battery top cover structure of Embodiment 1, a battery is disclosed, which mainly consists of a negative electrode top cover (1), an aluminum shell (2), a negative electrode current collector (3), a core (4), and a positive electrode current collector (5), as follows. Figure 4 As shown.

[0085] In one implementation example, the battery described above is a cylindrical lithium battery.

[0086] Specifically, the negative electrode top cover (1) and the negative electrode current collector (3) are electrically connected by laser welding. The negative electrode current collector (3) and the positive electrode current collector (5) are both electrically connected to the core (4) by laser welding. The positive electrode current collector (5) is also electrically connected to the aluminum shell (2) by laser welding, thus forming an aluminum shell (2) with a positive charge. Since the aluminum plate (104) of the negative electrode top cover (1) is electrically connected to the aluminum shell (2) by laser welding, the aluminum plate (104) of the negative electrode top cover (1) is positively charged, while the negative electrode post (101) is negatively charged, thus realizing the integration of positive and negative terminals.

[0087] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

[0088] While the specific embodiments of the present invention have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solutions of the present invention are still within the scope of protection of the present invention.

Claims

1. A battery top cover structure, characterized in that, The battery top cover aluminum plate (104) includes a flange structure (1041). The aluminum plate substrate in the middle of the aluminum plate (104) for setting the flange structure (1041) has a different thickness from the aluminum plate substrate in the middle periphery, and there is a gap between the flange structure (1041) and the aluminum plate substrate in the middle periphery to form a slot. The flange structure (1041) is also uniformly distributed with slot structures (1042), and the slot structures (1042) surround the flange structure (1041). The depth (L3) of the groove is in the range of 0 < L3 ≤ 2 mm; the distance L2 between the flange structure (1041) and the aluminum plate body is in the range of 0 < L2 ≤ 4 mm; the battery top cover structure also includes a negative electrode post (101), an injection-molded upper plastic (102), a fluororubber (103), and a lower plastic (105). The negative electrode post (101) includes a disk structure (1012) and a cylinder disposed on the disk structure (1012). A groove structure (1011) is provided on the cylindrical surface (1013) on the outer side of the cylinder. The fluororubber (103) is pressed onto the upper surface of the disk structure (1012) excluding the mounting cylinder, and the aluminum plate (104) is used to press onto the fluororubber (103); The injection-molded plastic (102) is used to incorporate the groove structure (1011). When the injection molding plastic (102) is injected into the component, the slot structure (1042) of the aluminum plate (104) and the grooving structure (1011) of the negative electrode post (101) respectively limit the aluminum plate (104) and the negative electrode post (101) radially and axially.

2. The battery top cover structure as described in claim 1, characterized in that, The depth (H1) of the groove structure (1011) is in the range of 0 < H1 ≤ 2 mm, and the height (L1) of the groove structure (1011) is in the range of 0 < L1 ≤ 4 mm.

3. The battery top cover structure as described in claim 1, characterized in that, The flange structure (1041) is formed by stamping and bending the aluminum plate substrate, and is an integral structure with the aluminum plate (104).

4. The battery top cover structure as described in claim 1, characterized in that, The thickness (D2) of the flange structure (1041) is in the range of 0.5mm≤D2≤2.5mm.

5. The battery top cover structure as described in claim 1, characterized in that, The relationship between the thickness (D2) of the flange structure (1041) and the thickness (D1) of the aluminum plate substrate in the middle periphery is: 0.2≤D2 / D1<1.

6. The assembly method of a battery top cover structure as described in any one of claims 1-5, characterized in that, include: The lower plastic (105) and fluororubber (103) are fitted onto the negative electrode post (101); Then, the aluminum plate (104) is pressed onto the fluororubber (103) and squeezed through the mold to ensure the compression of the fluororubber (103). At the same time, the assembled components are injected with plastic (102) into the mold. When the injection molding plastic (102) is injected into the component, the slot structure (1042) of the aluminum plate (104) and the grooving structure (1011) of the negative electrode post (101) respectively limit the aluminum plate (104) and the negative electrode post (101) radially and axially.

7. A battery, characterized in that, Includes the battery top cover structure as described in any one of claims 1-5, aluminum shell (2), negative electrode current collector (3), core (4), and positive electrode current collector (5); The battery top cover structure includes a negative electrode top cover (1), which is electrically connected to a negative electrode current collector (3). Both the negative electrode current collector (3) and the positive electrode current collector (5) are electrically connected to the core (4), and the positive electrode current collector (5) is also electrically connected to the aluminum shell (2).

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