Lithium ion battery with fusing mechanism

Abstract

The utility model belongs to the technical field of lithium ion batteries, and discloses a lithium ion battery with a fusing mechanism, which comprises a shell and a battery top cover hermetically matched at the upper end of the shell, a core bag is mounted in the shell, and a positive pole, a negative pole and an anti-explosion valve are mounted on the battery top cover. A positive bottom plate of the positive pole is connected with a positive lug of the core package, and a negative bottom plate of the negative pole is connected with a negative lug of the core package; an annular groove is formed in the width direction of the positive electrode bottom plate, and fixing glue for reinforcing is arranged in the annular groove in a matched manner; a fusing hole is formed in the middle of the annular groove, fusing hole connecting parts of the positive electrode bottom plate are arranged on the two sides of the fusing hole, the sum of the longitudinal sectional areas of the two fusing hole connecting parts is S1, the longitudinal sectional area of the positive electrode bottom plate is S2, and S1 is smaller than or equal to 0.1 * S2. According to the utility model, a fusing mechanism can be quickly triggered when the temperature reaches a dangerous threshold value, battery damage caused by overhigh temperature is avoided, and the safety and reliability of the lithium battery are improved.

Description

Technical Field

[0001] This utility model belongs to the field of lithium-ion battery technology, specifically relating to a lithium-ion battery with a built-in fuse mechanism. Background Technology

[0002] In today's society, lithium batteries are widely used in electric vehicles, portable electronic devices, and energy storage systems due to their advantages such as high energy density and long cycle life. However, lithium batteries face many safety hazards during use. Under abnormal conditions such as overcharging and short circuits, the positive electrode current will increase sharply, generating a large amount of heat, which may lead to serious consequences such as thermal runaway, combustion, or even explosion.

[0003] Existing lithium battery safety protection measures mainly focus on battery management systems and external circuit protection, lacking direct and effective solutions for overheating and overcurrent issues within the positive electrode. Therefore, designing a fusible structure capable of rapidly cutting off the positive electrode circuit under abnormal conditions is of crucial practical significance for improving the safety and reliability of lithium batteries.

[0004] In the field of lithium battery safety protection, existing protection technologies for the positive electrode have many significant drawbacks.

[0005] In terms of overcurrent protection, traditional fuses have a slow response speed and are unable to melt in time when the current surges instantaneously. When a lithium battery experiences an anomaly such as a short circuit, a large current is generated rapidly. Traditional fuses cannot quickly cut off the circuit, which can cause the positive electrode to be subjected to a continuous surge of current and heat up, leading to thermal runaway.

[0006] In terms of temperature sensing, existing temperature-sensitive elements have low accuracy and cannot accurately detect minute temperature changes at the positive electrode. They cannot detect and act in time when the temperature of the positive electrode rises slowly, and by the time the protection is triggered due to excessively high temperature, the battery may have already suffered irreversible damage.

[0007] Moreover, most existing technologies have poor integration with batteries, which increases the size and weight of batteries, hindering the miniaturization and lightweighting of batteries and increasing production costs. Utility Model Content

[0008] The purpose of this invention is to provide a lithium-ion battery with a built-in fuse mechanism to solve the aforementioned problems in the prior art.

[0009] To achieve the above objectives, the present invention adopts the following technical solution:

[0010] A lithium-ion battery with a built-in fuse mechanism includes a casing and a battery top cover sealed to the upper end of the casing. A core pack is installed inside the casing. A positive terminal, a negative terminal, and an explosion-proof valve are installed on the battery top cover. The positive base plate of the positive terminal is connected to the positive electrode tab of the core pack, and the negative base plate of the negative terminal is connected to the negative electrode tab of the core pack. An annular groove is provided in the width direction of the positive base plate, and a fixing adhesive for reinforcement is provided in the annular groove. A fuse hole is provided in the middle of the annular groove, and the two sides of the fuse hole are fuse hole connection parts of the positive base plate. The sum of the longitudinal cross-sectional areas of the two fuse hole connection parts is S1, and the longitudinal cross-sectional area of ​​the positive base plate is S2, where S1≤0.1*S2.

[0011] As a preferred technical solution of this utility model, the battery top cover includes a substrate and a top cover under plastic connected to the bottom surface of the substrate. Both ends of the substrate and both ends of the top cover under plastic are provided with corresponding electrode clearance holes. The electrode of the positive electrode and the electrode of the negative electrode are both inserted into the corresponding electrode clearance holes. The top cover under plastic is provided with a plurality of electrolyte exchange holes.

[0012] As a preferred technical solution of this utility model, at least one lower protrusion is provided on the plastic under the top cover through a structural recess forming on the bottom surface of the plastic under the top cover. The lower protrusion abuts against the core package, and each lower protrusion is provided with an electrolyte exchange hole.

[0013] As a preferred technical solution of this utility model, the plastic under the top cover is provided with lower protrusions on both sides and in the middle.

[0014] As a preferred technical solution of this utility model, a positive sealing ring is provided between the positive electrode post and the corresponding electrode post clearance hole, and a negative sealing ring is provided between the negative electrode post and the corresponding electrode post clearance hole.

[0015] As a preferred technical solution of this utility model, a positive electrode riveting block is provided on the top surface of the battery top cover, the positive electrode riveting block is connected to the positive electrode post, and a positive electrode plastic is provided between the positive electrode riveting block and the battery top cover.

[0016] As a preferred technical solution of this utility model, a negative electrode riveting block is provided on the top surface of the battery top cover. The negative electrode riveting block is connected to the electrode post of the negative electrode post. A negative electrode plastic is provided between the negative electrode riveting block and the battery top cover.

[0017] As a preferred technical solution of this utility model, the cross-sectional area of ​​the explosion-proof valve is ≥ 1 / 6 of the cross-sectional area of ​​the substrate.

[0018] As a preferred technical solution of this utility model, the upper end of the explosion-proof valve is provided with an explosion-proof valve protective film.

[0019] Beneficial effects: This utility model directly connects the positive electrode base plate of the positive electrode post to the positive electrode tab of the core pack, and directly connects the negative electrode base plate of the negative electrode post to the negative electrode tab of the core pack, reducing the current path. An annular groove is set in the width direction of the positive electrode base plate, and a fuse hole is opened in the middle of the annular groove. Fixing adhesive is matched in the annular groove to provide plastic protection at the fuse mechanism, so that it is not affected by external forces during operation. Without affecting battery performance and spatial layout, it effectively improves the safety performance of lithium battery and reduces production costs. The sum of the longitudinal cross-sectional areas of the connection part of the two fuse holes is less than 1 / 10 of the longitudinal cross-sectional area of ​​the positive electrode base plate, so that the formed fuse mechanism can quickly block excessive current, ensuring the safety of lithium battery use. It enables the positive electrode post to accurately sense the slight changes in positive electrode temperature and quickly trigger the fuse mechanism when the temperature reaches the dangerous threshold, avoiding battery damage caused by excessive temperature and improving the safety and reliability of lithium battery. Attached Figure Description

[0020] Figure 1 This is an exploded view of the present invention;

[0021] Figure 2 This is a three-dimensional schematic diagram of the present invention;

[0022] Figure 3 This is a three-dimensional schematic diagram of the positive electrode post in this utility model;

[0023] Figure 4 This is a partial structural diagram of the positive electrode post in this utility model;

[0024] Figure 5 This is a schematic diagram showing the connection between the positive and negative terminals and the core package in this utility model.

[0025] In the diagram: 1-Shell; 2-Battery top cover; 201-Baseboard; 202-Plastic under top cover; 3-Chip pack; 301-Positive electrode tab; 302-Negative electrode tab; 4-Positive electrode post; 401-Annular groove; 402-Fixing adhesive; 403-Fuse hole; 404-Fuse hole connection; 5-Negative electrode post; 6-Explosion-proof valve; 7-Positive electrode sealing ring; 8-Negative electrode sealing ring; 9-Positive electrode riveting block; 10-Plastic on top of positive electrode; 11-Riveting block on top of negative electrode; 12-Plastic on top of negative electrode; 13-Explosion-proof valve protective film. Detailed Implementation

[0026] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the present utility model will be briefly introduced below in conjunction with the accompanying drawings and descriptions of the embodiments or the prior art. Obviously, the following description of the structure of the accompanying drawings is only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. It should be noted that the description of these embodiments is used to help understand this utility model, but does not constitute a limitation on this utility model.

[0027] Example:

[0028] like Figures 1-5 As shown, this embodiment provides a lithium-ion battery with a built-in fuse mechanism, including a housing 1 and a battery top cover 2 sealed to the upper end of the housing 1. A core pack 3 is installed inside the housing 1. A positive electrode post 4, a negative electrode post 5, and an explosion-proof valve 6 are installed on the battery top cover 2. The positive electrode base plate of the positive electrode post 4 is connected to the positive electrode tab 301 of the core pack 3, and the negative electrode base plate of the negative electrode post 5 is connected to the negative electrode tab 302 of the core pack 3. Figure 5 As shown, the electrode tabs are directly connected to the base plate of the electrode post, reducing the current path. An annular groove 401 is provided in the width direction of the positive electrode base plate. A reinforcing adhesive 402 is fitted inside the annular groove 401 to provide plastic protection, preventing external forces from affecting the battery during operation. A fusible hole 403 is provided in the middle of the annular groove to form a fusible mechanism. The adhesive 402 wraps around the fusible mechanism, protecting it. The two sides of the fusible hole 403 are fusible hole connection portions 404 of the positive electrode base plate. The sum of the longitudinal cross-sectional areas of the two fusible hole connection portions 404 is S1, and the longitudinal cross-sectional area of ​​the positive electrode base plate is S2, where S1 ≤ 0.1 * S2. This design significantly reduces the current-carrying area while ensuring structural stability, enabling rapid interruption of excessive current during actual operation and ensuring the safety of the lithium battery.

[0029] This invention directly connects the positive electrode base plate of the positive electrode post 4 to the positive electrode tab 301 of the core pack 3, and directly connects the negative electrode base plate of the negative electrode post 5 to the negative electrode tab 302 of the core pack 3, reducing the current path. An annular groove 401 is provided in the width direction of the positive electrode base plate, and a fuse hole 403 is opened in the middle of the annular groove 401. A fixing adhesive 402 is matched in the annular groove 401 to provide plastic protection at the fuse mechanism, so that it is not affected by external forces during operation. Without affecting the battery performance and spatial layout, it effectively improves the safety performance of the lithium battery and reduces the production cost. The sum of the longitudinal cross-sectional areas of the two fuse hole connection parts 404 is less than 1 / 10 of the longitudinal cross-sectional area of ​​the positive electrode base plate, so that the formed fuse mechanism can quickly block excessive current, ensuring the safety of lithium battery use. The positive electrode post 4 can accurately sense the slight changes in the positive electrode temperature and quickly trigger the fuse mechanism when the temperature reaches the dangerous threshold, avoiding battery damage caused by excessive temperature and improving the safety and reliability of lithium battery.

[0030] As a preferred embodiment of this invention, it should be further explained that the battery top cover 2 includes a substrate 201 and a top cover under plastic 202 connected to the bottom surface of the substrate 201. Both ends of the substrate 201 and both ends of the top cover under plastic 202 are provided with corresponding electrode clearance holes. The electrode of the positive electrode 4 and the electrode of the negative electrode 5 are both inserted into the corresponding electrode clearance holes, which facilitates the matching and installation of the electrode. The top cover under plastic 202 is provided with multiple electrolyte exchange holes for electrolyte exchange during the battery cell cycle.

[0031] As a preferred embodiment of this example, it should be further explained that at least one lower protrusion is provided on the bottom surface of the plastic 202 under the top cover through a structural recess. The lower protrusion abuts against the core package 3. During assembly, the lower protrusion can be used to press down the core package to prevent the core package from shifting position. Each lower protrusion is provided with an electrolyte exchange hole, which does not affect electrolyte exchange.

[0032] As a preferred embodiment of this invention, it should be further noted that the plastic 202 under the top cover is provided with lower protrusions on both sides and in the middle. The battery top cover 2 is designed with a large area of ​​lower protrusion structure, which can better ensure the stability of the core pack.

[0033] As a preferred embodiment of this invention, it should be further explained that a positive electrode sealing ring 7 is provided between the electrode post 4 and the corresponding electrode post clearance hole, which can enhance the sealing performance of the positive electrode post 4. A negative electrode sealing ring 8 is provided between the electrode post 5 and the corresponding electrode post clearance hole, which can enhance the sealing performance of the negative electrode post 5.

[0034] As a preferred embodiment of this invention, it should be further explained that a positive electrode riveting block 9 is provided on the top surface of the battery top cover 2. The positive electrode riveting block 9 is connected to the electrode post of the positive electrode post 4 to ensure structural stability. A positive electrode plastic 10 is provided between the positive electrode riveting block 9 and the battery top cover 2 to achieve insulation.

[0035] As a preferred embodiment of this invention, it should be further explained that a negative electrode riveting block 11 is provided on the top surface of the battery top cover 2. The negative electrode riveting block 11 is connected to the electrode post of the negative electrode post 5 to ensure structural stability. A negative electrode plastic 12 is provided between the negative electrode riveting block 11 and the battery top cover 2 to achieve insulation.

[0036] As a preferred embodiment of this invention, it should be further noted that the cross-sectional area of ​​the explosion-proof valve 6 is ≥1 / 6 of the cross-sectional area of ​​the substrate, which enables more precise valve opening and provides a larger pressure relief area, thereby improving safety.

[0037] As a preferred embodiment of this invention, it should be further noted that the upper end of the explosion-proof valve 6 is provided with an explosion-proof valve protective film 13 to achieve the effect of dust prevention and water blocking.

[0038] Finally, it should be noted that the above description is merely a preferred embodiment of this utility model and is not intended to limit the scope of protection of this utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the scope of protection of this utility model.

Claims

1. A lithium-ion battery with a built-in fuse mechanism, comprising a casing (1) and a battery top cover (2) sealed to the upper end of the casing (1), wherein a core pack (3) is installed inside the casing (1), and a positive electrode post (4), a negative electrode post (5), and an explosion-proof valve (6) are installed on the battery top cover (2), characterized in that, The positive electrode base plate of the positive electrode post (4) is connected to the positive electrode tab (301) of the core package (3), and the negative electrode base plate of the negative electrode post (5) is connected to the negative electrode tab (302) of the core package (3). An annular groove (401) is provided in the width direction of the positive electrode base plate, and a fixing adhesive (402) for reinforcement is provided in the annular groove (401). A fusible hole (403) is provided in the middle of the annular groove, and the two sides of the fusible hole (403) are the fusible hole connection parts (404) of the positive electrode base plate. The sum of the longitudinal cross-sectional areas of the two fusible hole connection parts (404) is S1, and the longitudinal cross-sectional area of ​​the positive electrode base plate is S2, where S1≤0.1*S2.

2. A lithium-ion battery with a built-in fuse mechanism according to claim 1, characterized in that, The battery top cover (2) includes a substrate (201) and a top cover under plastic (202) connected to the bottom surface of the substrate (201). Both ends of the substrate (201) and both ends of the top cover under plastic (202) are provided with corresponding electrode clearance holes. The electrode of the positive electrode (4) and the electrode of the negative electrode (5) are both inserted into the corresponding electrode clearance holes. The top cover under plastic (202) is provided with multiple electrolyte exchange holes.

3. A lithium-ion battery with a built-in fuse mechanism according to claim 2, characterized in that, At least one lower protrusion is provided on the plastic under the top cover (202) through a structural recess forming on the bottom surface of the plastic under the top cover (202). The lower protrusion abuts against the core package (3), and each lower protrusion is provided with an electrolyte exchange hole.

4. A lithium-ion battery with a built-in fuse mechanism according to claim 3, characterized in that, The lower plastic (202) of the top cover is provided with lower protrusions on both sides and in the middle.

5. A lithium-ion battery with a built-in fuse mechanism according to any one of claims 2-4, characterized in that, A positive electrode sealing ring (7) is provided between the electrode post (4) and the corresponding electrode post clearance hole, and a negative electrode sealing ring (8) is provided between the electrode post (5) and the corresponding electrode post clearance hole.

6. A lithium-ion battery with a built-in fuse mechanism according to any one of claims 1-4, characterized in that, The top surface of the battery top cover (2) is provided with a positive electrode riveting block (9), which is connected to the positive electrode post (4). A positive electrode plastic (10) is provided between the positive electrode riveting block (9) and the battery top cover (2).

7. A lithium-ion battery with a built-in fuse mechanism according to any one of claims 1-4, characterized in that, The top surface of the battery top cover (2) is provided with a negative electrode riveting block (11), which is connected to the electrode post of the negative electrode post (5). A negative electrode plastic (12) is provided between the negative electrode riveting block (11) and the battery top cover (2).

8. A lithium-ion battery with a built-in fuse mechanism according to any one of claims 2-4, characterized in that, The cross-sectional area of ​​the explosion-proof valve (6) is ≥ 1 / 6 of the cross-sectional area of ​​the substrate.

9. A lithium-ion battery with a built-in fuse mechanism according to claim 8, characterized in that, An explosion-proof valve protective film (13) is provided at the upper end of the explosion-proof valve (6).

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