Novel square steel shell lithium battery assembly

Abstract

The utility model relates to the technical field of lithium batteries, and discloses a novel square steel shell lithium battery assembly. The novel square steel shell lithium battery assembly comprises a shell with the two ends open, a battery cell is arranged in the shell and connected with a positive electrode lug and a negative electrode lug, a top cover is welded to the opening in the top end of the shell, and a bottom cover is welded to the opening in the bottom end of the shell; a clearance hole is formed in the top cover, an insulating sealant layer is arranged on the end face of the top cover around the clearance hole, a positive pole penetrates through the clearance hole, and the positive pole is in insulated and sealed connection with the top cover through the insulating sealant layer; the free end of the positive tab is connected to the positive pole, and the free end of the negative tab is connected to the bottom of the top cover. Under the structure, the positive pole is in sealed connection with the top cover through heating fusion of the insulating sealant layer, so that the risk of liquid leakage easily caused by unstable sealing performance of a traditional riveting structure is effectively avoided. On the other hand, the problems that a traditional shell is large in machining difficulty and high in machining cost are solved.

Description

Technical Field

[0001] This utility model relates to the field of lithium battery technology, specifically a novel square steel-shell lithium battery assembly. Background Technology

[0002] As a type of clean energy, lithium batteries have been widely used in various electronic products due to their many advantages, such as high voltage, long charge and discharge life, low environmental pollution, and low self-discharge rate. Among them, steel-cased lithium batteries have also received considerable attention because their outer shell is made of steel, which gives them greater hardness. At the same time, their high energy density and fast charging characteristics make them suitable for use in devices that may be subject to collisions.

[0003] Traditional steel-cased lithium batteries generally consist of a battery cell, a steel casing (referred to as the steel casing) encapsulating the battery cell, and a cover plate attached to the steel casing. However, in existing technologies, steel casings using deep-drawing processes typically have the cover plate encapsulated at the top, while those using shallow-drawing processes typically have the cover plate encapsulated on the side. Both of these steel casing structures are not only difficult to manufacture, but also quite costly. More importantly, in existing technologies, the positive electrode lead (positive electrode post) on the cover plate of steel-cased lithium batteries is usually encapsulated and connected using a riveting process. This involves compressing the sealing ring and then riveting the electrode post to the cover plate. This riveting structure exhibits extremely unstable sealing performance under high temperature, high humidity, and alternating high and low temperature environments, easily leading to the risk of leakage.

[0004] Therefore, there is an urgent need for a new type of square steel-cased lithium battery assembly to solve the above problems. Utility Model Content

[0005] Based on the above, the purpose of this utility model is to provide a novel square steel-shell lithium battery assembly to solve the problems of high processing difficulty and cost of steel-shell lithium batteries in the prior art, as well as the risk of leakage caused by the positive electrode post riveting structure.

[0006] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0007] This utility model provides a novel square steel-shell lithium battery assembly, comprising a shell with openings at both ends, a battery cell inside the shell, a positive electrode tab and a negative electrode tab connected to the battery cell, a top cover welded to the top opening of the shell, and a bottom cover welded to the bottom opening; the top cover has a clearance hole, and an insulating sealant layer is provided around the clearance hole on the end face of the top cover; a positive electrode post passes through the clearance hole, and the positive electrode post is insulated and sealed to the top cover through the insulating sealant layer;

[0008] The free end of the positive electrode tab is connected to the positive electrode post, and the free end of the negative electrode tab is connected to the bottom of the top cover.

[0009] As an optional technical solution for a novel square steel-cased lithium battery assembly, the positive electrode post includes a connecting part and an extension integrally formed thereon. The free end of the extension passes through the insulating sealant layer and the vent hole in sequence and extends to the bottom of the top cover. The positive electrode tab is electrically connected to the extension.

[0010] As an alternative technical solution for a novel square steel-cased lithium battery assembly, the diameter of the connecting portion is larger than the diameter of the vent hole, and the diameter of the extension portion is smaller than the diameter of the vent hole.

[0011] As an optional technical solution for a novel square steel-cased lithium battery assembly, the top cover and bottom cover are respectively provided with integrally formed protrusions at their circumferential edges. The protrusions are laser-welded to the opening of the casing, and the free end of the protrusion is flush with the end of the opening of the casing.

[0012] As an alternative technical solution for a novel square steel-cased lithium battery assembly, the protrusion and the bend of the top or bottom cover have a smooth transition.

[0013] As an optional technical solution for a novel square steel-cased lithium battery assembly, the top cover is provided with an injection hole, and a sealing component is connected to the injection hole.

[0014] As an optional technical solution for a novel square steel-cased lithium battery assembly, the sealing component is a metal sealing plate, the sealing plate being larger than the diameter of the injection hole, and the sealing plate being welded to the top cover to seal the injection hole.

[0015] As an optional technical solution for a novel square steel-shell lithium battery assembly, the sealing assembly includes a base and an explosion-proof top cover. The base is welded to the end face of the top cover, and the base is provided with an explosion-proof hole. The explosion-proof hole and the liquid injection hole are coaxially arranged. A sealant layer is coated around the explosion-proof hole on the base. The base is sealed to the explosion-proof top cover through the sealant layer and blocks the explosion-proof hole.

[0016] The beneficial effects of this utility model are as follows:

[0017] This utility model provides a novel square steel-shell lithium battery assembly, which includes a shell with openings at both ends, a battery cell inside the shell, a positive electrode tab and a negative electrode tab connected to the battery cell, a top cover welded to the top opening of the shell, and a bottom cover welded to the bottom opening; the top cover has a clearance hole, and an insulating sealant layer is provided around the clearance hole on the end face of the top cover, and a positive electrode post passes through the clearance hole, and the positive electrode post is insulated and sealed to the top cover through the insulating sealant layer; the free end of the positive electrode tab is connected to the positive electrode post, and the free end of the negative electrode tab is connected to the bottom of the top cover.

[0018] In the above structure, the positive electrode post is sealed to the top cover by heating and fusion with an insulating sealant layer. This effectively avoids the risk of leakage caused by the unstable sealing performance of traditional positive electrode posts due to riveting structures in high temperature, high humidity, and alternating high and low temperature environments. On the other hand, the opening structure at both ends of the casing and the protruding structure at the circumferential edges of the top and bottom covers facilitate the welding and sealing connection of the battery cell after assembly and positioning, reducing the problems of high processing difficulty and high processing cost of traditional casings. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the overall structure of the novel square steel-shell lithium battery module in Embodiment 1 of this utility model;

[0020] Figure 2 This is an exploded view of the novel square steel-shell lithium battery assembly in Embodiment 1 of this utility model;

[0021] Figure 3 This is a partial cross-sectional schematic diagram of the novel square steel-shell lithium battery assembly in Embodiment 1 of this utility model;

[0022] Figure 4 for Figure 3 Enlarged view of point A in the middle;

[0023] Figure 5 This is a schematic diagram of the positive electrode post in Embodiment 1 of this utility model;

[0024] Figure 6 This is a schematic diagram of the sealing assembly in Embodiment 2 of this utility model;

[0025] Figure 7 This is a cross-sectional schematic diagram of the sealing component in Embodiment 2 of this utility model.

[0026] In the picture:

[0027] 1. Casing; 10. Battery cell; 11. Positive electrode tab; 12. Negative electrode tab;

[0028] 2. Top cover; 20. Void hole; 21. Insulating sealant layer; 22. Positive electrode post; 220. Connecting part; 221. Extension part; 23. Protrusion part; 24. Injection hole; 25. Sealing assembly; 251. Sealing plate; 252. Base; 253. Explosion-proof hole; 254. Sealing layer; 255. Explosion-proof top cover;

[0029] 3. Bottom cover. Detailed Implementation

[0030] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, not the entire structure.

[0031] In the description of this utility model, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0032] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0033] In the description of this embodiment, terms such as "upper," "lower," "left," and "right" are based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of description and simplification of operation, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0034] In the description of this utility model, unless otherwise stated, "a plurality of" means two or more. Furthermore, the terms "first" and "second" are used merely for descriptive distinction and have no specific meaning.

[0035] Example 1

[0036] like Figure 1-5As shown, this utility model provides a novel square steel-shell lithium battery assembly. The novel square steel-shell lithium battery assembly includes a shell 1 with openings at both ends. A battery cell 10 is provided inside the shell 1. A positive electrode tab 11 and a negative electrode tab 12 are connected to the battery cell 10. A top cover 2 is welded to the top opening of the shell 1, and a bottom cover 3 is welded to the bottom opening. The top cover 2 has a clearance hole 20. An insulating sealant layer 21 is provided around the clearance hole 20 on the end face of the top cover 2. A positive electrode post 22 passes through the clearance hole 20. The positive electrode post 22 is insulated and sealed to the top cover 2 through the insulating sealant layer 21. The free end of the positive electrode tab 11 is connected to the positive electrode post 22, and the free end of the negative electrode tab 12 is connected to the bottom of the top cover 2.

[0037] This utility model provides a novel square steel-cased lithium battery assembly that uses an insulating sealant layer 21 to heat-fuse the positive electrode post 22 with the top cover 2 for a sealed connection. This effectively avoids the risk of leakage caused by the unstable sealing performance of the traditional positive electrode post 22 due to its riveted structure under high temperature, high humidity, and alternating high and low temperature environments. On the other hand, the opening structure at both ends of the casing 1 and the protrusions 23 at the circumferential edges of the top cover 2 and bottom cover 3 facilitate the welding and sealing connection of the battery cell 10 after it is installed and positioned in the casing, reducing the problems of high processing difficulty and high processing cost of the traditional casing 1.

[0038] Specifically, such as Figure 2-4 As shown, the top cover 2 has an integrally formed protrusion 23 at its circumferential edge. The protrusion 23 is laser-welded to the top opening of the housing 1, and the free end of the protrusion 23 is flush with the top opening of the housing 1. The bottom cover 3 has an integrally formed protrusion 23 at its circumferential edge. The protrusion 23 is laser-welded to the bottom opening of the housing 1, and the free end of the protrusion 23 is flush with the bottom opening of the housing 1. In this structure, the protrusion 23 not only improves the operability of welding the top cover 2, bottom cover 3 and housing 1, but also improves the connection between the top cover 2, bottom cover 3 and housing 1. The airtight seal makes the connection between the three components more stable and reliable. On the other hand, after the top cover 2 and the shell 1 are sealed together, the top height of the positive electrode post 22 will not be higher than the end of the shell 1, making the overall structure of the new square steel shell lithium battery assembly more compact and simple, improving the stability of the new square steel shell lithium battery assembly during transportation or installation, and effectively preventing the risk of collision or short circuit caused by the protrusion of the positive electrode post 22. The protrusion 23 and the bend of the top cover 2 or bottom cover 3 are smoothly transitioned, which further improves the operability and stability of welding between the top cover 2 and bottom cover 3 and the openings at both ends of the shell 1.

[0039] Furthermore, such as Figure 2 and Figure 5As shown, the positive electrode post 22 consists of a connecting part 220 and an extension part 221 integrally formed with the connecting part 220. The bottom end (free end) of the extension part 221 is sequentially perforated with an insulating sealant layer 21 and a clearance hole 20, extending to the bottom of the top cover 2. The positive electrode tab 11 is electrically connected to the bottom end of the extension part 221 by laser welding. It should be noted that the insulating sealant layer 21 can be one of silicone rubber, polyurethane, or acrylate, but is not limited to these materials. The diameter of the connecting part 220 is larger than the diameter of the clearance hole 20, allowing the connecting part 220 to be stably and securely bonded to the top surface of the top cover 2 through the insulating sealant layer 21. In other words, the insulating sealant layer 21 between the connecting part 220 and the top cover 2 tightly bonds them together through molecular hydrogen bonds, improving the sealing stability between the positive electrode post 22 and the top cover 2. The diameter of the extension 221 is smaller than the diameter of the vent hole 20. After the positive electrode post 22 and the top cover 2 are sealed and positioned, there is a certain safe distance between the circumferential edges of the extension 221 and the vent hole 20, which effectively prevents short circuits between the positive and negative electrodes from causing safety hazards.

[0040] In this embodiment, as Figure 2 As shown, the top cover 2 is provided with a liquid injection hole 24, and a sealing component 25 is connected to the liquid injection hole 24. It should be noted that, in this embodiment, the sealing component 25 is a metal sealing plate 251 (e.g., a stainless steel sealing plate) welded to the liquid injection hole 24, and the diameter of the sealing plate 251 is larger than the diameter of the liquid injection hole 24. The sealing plate 251 is laser-welded to the end face of the top cover 2 to seal the liquid injection hole 24, which improves the sealing performance of the liquid injection hole 24 and effectively prevents the risk of leakage.

[0041] Example 2

[0042] like Figure 6 and Figure 7As shown, the difference between this embodiment and Embodiment 1 is that in this embodiment, the sealing component 25 is a three-component sealing explosion-proof valve, namely, a base 252 laser-welded to the upper surface of the top cover 2, an explosion-proof hole 253 provided on the base 252, and the explosion-proof hole 253 and the liquid injection hole 24 are coaxially arranged; a sealing adhesive layer 254 is coated around the explosion-proof hole 253 on the base 252, and an explosion-proof top cover 255 is provided above the sealing adhesive layer 254. The explosion-proof top cover 255 is sealed to the base 252 through the sealing adhesive layer 254 and seals the explosion-proof hole 253; it should be noted that when the temperature inside the shell 1 reaches a certain threshold (110°), the adhesiveness of the sealing adhesive layer 254 will decrease sharply, and the explosion-proof top cover 255 will lose its adhesiveness and detach, so that the inside of the shell 1 can communicate with the outside through the explosion-proof hole 253 to release pressure, thereby improving the safety of the new square steel shell lithium battery component. On the other hand, when the battery cell 10 inside the housing 1 is in an environment with normal temperature and below 110 degrees, the explosion-proof cover 255 plays a sealing role, effectively preventing the risk of leakage.

[0043] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model in any way. Although the present utility model has been disclosed above with reference to a preferred embodiment, it is not intended to limit the present utility model. Any person skilled in the art can make some changes or modifications to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present utility model. Any simple modifications, equivalent changes, and modifications made to the above embodiments based on the present utility model without departing from the scope of the present utility model shall fall within the scope of the present utility model.

Claims

1. A novel square steel-cased lithium battery assembly, comprising a casing with openings at both ends, wherein a battery cell is disposed within the casing, and a positive electrode tab and a negative electrode tab are connected to the battery cell, characterized in that, The top opening of the housing is welded with a top cover, and the bottom opening is welded with a bottom cover; the top cover is provided with a clearance hole, and the end face of the top cover is provided with an insulating sealant layer around the clearance hole; a positive electrode post is inserted into the clearance hole, and the positive electrode post is connected to the top cover in an insulating and sealed manner through the insulating sealant layer. The free end of the positive electrode tab is connected to the positive electrode post, and the free end of the negative electrode tab is connected to the bottom of the top cover.

2. The novel square steel-cased lithium battery module according to claim 1, characterized in that, The positive electrode post includes a connecting part and an extension integrally formed thereon. The free end of the extension passes through the insulating sealant layer and the vent hole in sequence and extends to the bottom of the top cover. The positive electrode tab is electrically connected to the extension.

3. A novel square steel-cased lithium battery module according to claim 2, characterized in that, The diameter of the connecting portion is larger than the diameter of the vent hole, and the diameter of the extension portion is smaller than the diameter of the vent hole.

4. A novel square steel-cased lithium battery assembly according to claim 1, characterized in that, The top cover and bottom cover are respectively provided with integrally formed protrusions at their circumferential edges. The protrusions are laser-welded to the opening of the shell, and the free end of the protrusion is flush with the end of the opening of the shell.

5. A novel square steel-cased lithium battery assembly according to claim 4, characterized in that, The protrusion and the bend of the top or bottom cover are smoothly transitioned.

6. A novel square steel-cased lithium battery module according to claim 1, characterized in that, The top cover is provided with a liquid injection hole, and a sealing component is connected to the liquid injection hole.

7. A novel square steel-cased lithium battery assembly according to claim 6, characterized in that, The sealing component is a metal sealing plate, which is larger than the diameter of the injection hole. The sealing plate is welded to the top cover to seal the injection hole.

8. A novel square steel-cased lithium battery module according to claim 6, characterized in that, The sealing assembly includes a base and an explosion-proof top cover. The base is welded to the end face of the top cover. The base has an explosion-proof hole, which is coaxially arranged with the injection hole. A sealant layer is applied around the explosion-proof hole on the base. The base is sealed to the explosion-proof top cover through the sealant layer and blocks the explosion-proof hole.

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