A lithium-ion battery positive tab and a lithium-ion battery

Abstract

The utility model provides a kind of lithium ion battery positive pole lug and lithium ion battery, it is related to lithium ion battery technical field, including: shell, shell inside is equipped with battery body, and battery body top is connected with positive pole piece and negative pole piece respectively, and positive pole piece top is equipped with two positive pole lug. This kind of through the design of double pole lug, ensure that current distribution is more uniform, reduce resistance, improve the security and efficiency of battery, while designing U-shaped groove on pole lug, can increase the mechanical connection strength between pole lug and current collector, can also effectively disperse thermal stress in welding process and mechanical stress in use process.

Description

Technical Field

[0001] This utility model relates to the field of lithium-ion battery technology, specifically to the positive electrode tab of a lithium-ion battery and a lithium-ion battery. Background Technology

[0002] Lithium-ion batteries are widely used in consumer electronics, electric vehicles, and energy storage systems due to their advantages such as high energy density, long cycle life, and low self-discharge rate. In the structure of lithium-ion batteries, the tabs, as important current-conducting components connecting electrode materials and external circuits, have a significant impact on the battery's internal resistance, thermal stability, rate performance, and cycle life.

[0003] Existing lithium-ion batteries typically use a single tab layout for the positive electrode, which is fixed to the positive electrode plate by welding. However, during use, the single tab design can easily lead to current concentration, causing overheating at the connection between the tab and the electrode plate, which affects the battery's performance. At the same time, during the charging and discharging process, the positive electrode plate will expand and contract in volume, making the existing tabs prone to fatigue damage. Utility Model Content

[0004] The present invention aims to address the shortcomings of the prior art by providing a positive electrode tab for a lithium-ion battery and a lithium-ion battery. The design of the double electrode tabs ensures a more uniform current distribution, reduces resistance, and improves the safety and efficiency of the battery. At the same time, the design of the U-shaped groove on the electrode tabs increases the mechanical connection strength between the electrode tabs and the current collector, and can also effectively disperse the thermal stress during the welding process and the mechanical stress during use.

[0005] To achieve the above objectives, this utility model provides the following technical solution: a lithium-ion battery positive electrode tab and a lithium-ion battery, comprising:

[0006] The housing contains a battery body, and a positive electrode plate and a negative electrode plate are respectively connected to the top of the battery body. The top of the positive electrode plate has two positive tabs.

[0007] Furthermore, the two positive tabs are located on the same side of the positive electrode plate, and three slots are formed at the bottom of the positive tabs, and the three slots are evenly distributed.

[0008] Furthermore, the positive electrode tab is provided with multiple solder joints, and the slot is located between two adjacent solder joints.

[0009] Furthermore, the length of the slot is shorter than half the width of the positive electrode tab, the slot is a U-shaped slot, and the solder joints are evenly distributed.

[0010] Furthermore, a negative electrode tab is welded to the surface of the negative electrode sheet, and the tops of the positive and negative electrode tabs protrude from the upper surface of the housing. An insulator is provided between the housing and the positive and negative electrode tabs.

[0011] Furthermore, the positive electrode tab protruding from the outer side of the housing is provided with a protective coating, and the protective coating is polyimide tape.

[0012] Furthermore, the positive electrode tab has a U-shaped zigzag design in the middle.

[0013] The advantages of this invention are that the design of the double tabs ensures a more uniform current distribution, reduces resistance, and improves the safety and efficiency of the battery. At the same time, the U-shaped groove on the tabs increases the mechanical connection strength between the tabs and the current collector, and can effectively disperse the thermal stress during welding and the mechanical stress during use. In addition, the U-shaped bend in the middle of the positive tab provides additional elastic space, which helps to absorb the volume changes generated by the battery during charging and discharging and reduce mechanical stress. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the overall structure of this utility model.

[0015] Figure 2 This is a cross-sectional view of the overall structure of this utility model.

[0016] Figure 3 This is a side sectional view of the overall structure of this utility model.

[0017] Figure 4 This is a half-sectional view of the overall structure of this utility model.

[0018] Figure 5 This is a schematic diagram of the battery body structure of this utility model.

[0019] Figure 6 For the present utility model Figure 2 Enlarged view of point A in the image.

[0020] Figure 1-6 In the middle: 1. Casing; 2. Battery body; 201. Negative electrode; 202. Positive electrode; 3. Positive electrode tab; 301. Groove; 302. Solder joint; 4. Insulator; 401. Protective coating; 5. Negative electrode tab. Detailed Implementation

[0021] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0022] The following disclosure provides many different embodiments or examples for implementing different structures of this application. To simplify the disclosure, specific examples of components and arrangements are described below. Of course, these are merely examples and are not intended to limit the scope of this application. Furthermore, reference numerals and / or letters may be repeated in different examples; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. In addition, various specific examples of processes and materials are provided in this application, but those skilled in the art will recognize the application of other processes and / or the use of other materials.

[0023] This application provides a positive electrode tab for a lithium-ion battery and a lithium-ion battery. The following provides a detailed description of the positive electrode tab and the lithium-ion battery. It should be noted that the order of description of the following embodiments is not intended to limit the preferred order of the embodiments.

[0024] The present application will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0025] Please see Figure 1-6 In this embodiment, a lithium-ion battery positive electrode tab and a lithium-ion battery are provided, including: a housing 1, a battery body 2 inside the housing 1, a positive electrode 202 and a negative electrode 201 respectively connected to the top of the battery body 2, and two positive electrode tabs 3 provided on the top of the positive electrode 202.

[0026] Among them, the positive electrode 3 is made of aluminum, and the negative electrode is made of copper.

[0027] The design of the bipolar tabs ensures a more uniform current distribution, reduces resistance, and improves battery safety and efficiency. The U-shaped slot 301 on the positive tab 3 increases the mechanical connection strength between the positive tab and the positive electrode plate 202, and effectively disperses thermal stress during welding and mechanical stress during use. The U-shaped bend in the middle of the positive tab 3 provides additional elastic space, which helps to absorb the volume changes generated during battery charging and discharging and reduce mechanical stress.

[0028] Among them, the two positive tabs 3 are located on the same side of the positive electrode plate 202. The bottom of the positive tab 3 has three slots 301, and the three slots 301 are evenly distributed. The length of the slots 301 is less than half the width of the positive tab 3. The slots 301 are U-shaped. The solder points 302 are evenly distributed. The positive tab 3 has multiple solder points 302, and the slots 301 are located between two adjacent solder points 302. The middle part of the positive tab 3 has a U-shaped zigzag design.

[0029] Two positive tabs 3 are provided on the same side of the positive electrode 202, which can ensure that the current transmission path from the positive electrode 202 to the positive tab 3 is the shortest and most uniform, which helps to reduce resistance and reduce the risk of local overheating. The U-shaped groove design of the slot 301 serves two purposes. First, during charging and discharging, lithium ions are deintercalated from the negative electrode, migrate to the positive electrode through the electrolyte, and embed into the crystal structure of the positive electrode material. At this time, the crystal parameters of the positive electrode material change, causing the crystal volume to expand. The U-shaped groove absorbs stress through elastic deformation, avoiding stress concentration at the weld root. The groove opening disperses the periodic load of the repeated expansion and contraction of the positive electrode 202, reducing microcracks caused by metal fatigue. Then, the U-shaped zigzag design in the middle of the positive tab 3 provides a certain elastic space as a buffer, reducing the mechanical stress caused by volume change, thereby reducing the risk of tab breakage. Second, increasing the length of the positive tab 3 disperses the current density and reduces local heat generation.

[0030] The negative electrode sheet 201 has a negative electrode tab 5 welded to its surface. The positive electrode tab 3 and the negative electrode tab 5 protrude from the top surface of the housing 1. An insulator 4 is provided between the housing 1 and the positive electrode tab 3 and the negative electrode tab 5. The insulator 4 is made of polyimide, which has the characteristics of high temperature resistance, HF corrosion resistance and high mechanical strength. It can provide reliable electrical isolation between the positive electrode tab 3, the negative electrode tab 5 and the housing 1, effectively preventing internal short circuits. At the same time, polyimide has excellent high temperature resistance, which can maintain the overall stability of the battery during the charging and discharging process and prevent safety problems caused by overheating.

[0031] The positive electrode tab 3 protrudes from the outer side of the shell 1 and is provided with a protective coating 401. The protective coating 401 is a polyimide tape. The polyimide tape has the characteristics of high temperature resistance and chemical corrosion resistance. Its thickness is usually 25-50μm. It is applied to the positive electrode tab 3 by dispensing or spraying. After curing, it forms a dense protective layer to prevent the positive electrode tab 3 from being corroded during use, thereby affecting the service life of the positive electrode tab 3.

[0032] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0033] The foregoing has provided a detailed description of a lithium-ion battery positive electrode tab and a lithium-ion battery according to the embodiments of this application. Specific examples have been used to illustrate the principles and implementation methods of this application. The description of the above embodiments is only for the purpose of helping to understand the technical solutions and core ideas of this application. Those skilled in the art should understand that they can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A positive electrode tab for a lithium-ion battery and a lithium-ion battery, characterized in that, include: The housing (1) has a battery body (2) inside. The top of the battery body (2) is connected to a positive electrode plate (202) and a negative electrode plate (201). The top of the positive electrode plate (202) has two positive electrode tabs (3).

2. The lithium-ion battery positive electrode tab and lithium-ion battery according to claim 1, characterized in that, The two positive tabs (3) are located on the same side of the positive electrode plate (202), and the bottom of the positive tabs (3) has three slots (301) and the three slots (301) are evenly distributed.

3. The lithium-ion battery positive electrode tab and lithium-ion battery according to claim 2, characterized in that, The positive electrode tab (3) is provided with multiple solder points (302), and the slot (301) is located between two adjacent solder points (302), and the solder points (302) are evenly distributed.

4. The lithium-ion battery positive electrode tab and lithium-ion battery according to claim 2, characterized in that, The length of the slot (301) is less than half the width of the positive electrode tab (3), and the slot (301) is a U-shaped slot.

5. The lithium-ion battery positive electrode tab and lithium-ion battery according to claim 1, characterized in that, The negative electrode sheet (201) has a negative electrode tab (5) welded on its surface. The tops of the positive electrode tab (3) and the negative electrode tab (5) protrude from the upper surface of the housing (1). An insulator (4) is provided between the housing (1) and the positive electrode tab (3) and the negative electrode tab (5).

6. The lithium-ion battery positive electrode tab and lithium-ion battery according to claim 4, characterized in that, The positive electrode tab (3) protruding from the outer side of the housing (1) is provided with a protective coating (401), and the protective coating (401) is a polyimide tape.

7. The lithium-ion battery positive electrode tab and lithium-ion battery according to claim 1, characterized in that, The positive electrode tab (3) has a U-shaped zigzag design in the middle.

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