Tab structure, pole piece and lithium battery

Abstract

The utility model relates to a tab structure, a pole piece and a lithium battery, the tab structure is positioned on the pole piece and comprises a tab body, and a plurality of grooves are formed in one side, far away from the pole piece, of the tab body at intervals. The plurality of grooves are formed in one side of the tab body at intervals, so that the effective contact area of the tab and a collector plate is increased, the overcurrent capacity of the tab is improved, the rate capability of the battery is improved, the cycle performance of the battery meets the requirement under a certain rate, the effective internal space of the battery can be saved, and the service life of the battery is prolonged. Therefore, the problems of poor rate capability and poor cycle performance of the existing battery adopting a full-tab rectangular structure are effectively solved.

Description

Technical Field

[0001] The utility model relates to the technical field of lithium batteries, in particular to a pole ear structure and a pole piece, and a lithium battery. Background Art

[0002] With the development of power lithium-ion battery technology and the increasing attention paid to energy conservation and environmental protection, the application fields of lithium batteries are becoming more and more extensive, such as portable electronic products, electric vehicles, solar power generation systems and other new energy fields. Nowadays, people have higher requirements for lithium-ion batteries, especially for driving range, fast charging performance and cycle performance. If these performances are improved, the design of the tab structure is crucial.

[0003] At present, the most commonly used tab design structure is a full-tab rectangular structure. This structure has a simple manufacturing process, but it ignores the fact that this structure has a great impact on the performance of full-tab cylindrical batteries. This tab design has the following problems: 1) Poor rate performance: This structure has a small effective contact area with the collector plate and poor current capacity; 2) Low space utilization: Half of the tab part does not have current capacity, but occupies the effective space inside the battery cell; 3) Poor cycle performance: Due to poor current capacity, the cycle performance at a certain rate cannot meet the battery development requirements. Utility Model Content

[0004] Based on this, it is necessary to address the technical problems that the current lithium battery pole lugs are full-pole-lug rectangular structures, have poor rate performance, low space utilization and poor cycle performance. The utility model provides a pole lug structure, a pole piece and a lithium battery.

[0005] The utility model provides a pole ear structure, which is located on a pole piece and comprises a pole ear body. A side of the pole ear body away from the pole piece is provided with a plurality of grooves at intervals.

[0006] The utility model increases the effective contact area between the pole ear and the current collecting plate by providing a plurality of grooves at intervals on one side of the pole ear body, thereby increasing the current carrying capacity of the pole ear and improving the battery rate performance. Under a certain rate, the cycle performance of the battery meets the requirements and can also save effective internal space of the battery, thereby effectively solving the problems of poor rate performance and poor cycle performance of the existing battery adopting a full-pole ear rectangular structure.

[0007] As a further improvement of the above solution of the utility model, the groove has a V-shaped, trapezoidal or arc-shaped cross-section.

[0008] As a further improvement of the above solution of the utility model, the groove has a V-shaped cross-section.

[0009] As a further improvement of the above solution of the utility model, the distance between any two adjacent grooves is equal and the distance between any two adjacent grooves is 6-18 mm.

[0010] As a further improvement of the above solution of the utility model, a tooth portion is formed between any two adjacent grooves on the tab body, and the tooth portion has a triangular cross-section.

[0011] As a further improvement of the above solution of the utility model, the width of the tab body is 4-20 mm.

[0012] As a further improvement of the above solution of the utility model, the distance between the groove and the coating area of ​​the pole piece is greater than 0 and less than 20 mm.

[0013] As a further improvement of the above solution of the utility model, the tab body adopts an aluminum foil with a thickness of 8-25 μm or a copper foil with a thickness of 4-15 μm.

[0014] The utility model also provides a pole piece, which comprises the pole ear structure as mentioned above.

[0015] The utility model also provides a lithium battery, which comprises the pole piece as mentioned above.

[0016] Compared with the prior art, the utility model has the following beneficial effects:

[0017] The utility model increases the effective contact area between the pole ear and the current collecting plate by providing a plurality of grooves at intervals on one side of the pole ear body, thereby increasing the current carrying capacity of the pole ear and improving the battery rate performance. Under a certain rate, the cycle performance of the battery meets the requirements and can also save effective internal space of the battery, thereby effectively solving the problems of poor rate performance and poor cycle performance of the existing battery adopting a full-pole ear rectangular structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 A schematic structural diagram of a tab structure proposed in an embodiment of the utility model.

[0019] Figure numerals: 1, pole piece; 2, pole ear body; 2-1, groove; 2-2, tooth portion. DETAILED DESCRIPTION

[0020] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0021] At present, the pole lugs of lithium batteries are of a full-pole-lug rectangular structure, which has technical problems such as poor rate performance, low space utilization and poor cycle performance. To this end, this embodiment provides a pole lug structure to solve the problems of poor rate performance and poor cycle performance of existing batteries with a full-pole-lug rectangular structure.

[0022] Reference Figure 1 The tab structure of this embodiment includes a tab body 2 connected to a pole piece 1. The pole piece 1 mentioned here can be a positive pole piece or a negative pole piece.

[0023] A plurality of grooves 2-1 are provided at intervals on one side of the tab body 2 away from the pole piece 1. The provision of the plurality of grooves 2-1 increases the effective contact area between the tab and the current collecting plate, increases the current carrying capacity of the tab, improves the rate performance of the battery, enables the cycle performance of the battery to meet the requirements at a certain rate, and can also save effective internal space of the battery, thereby effectively solving the problems of poor rate performance and poor cycle performance of the existing battery using a full-tab rectangular structure.

[0024] In this embodiment, the groove 2-1 is a groove 2-1 with a V-shaped cross-section. Of course, in other embodiments, the groove 2-1 may also be a groove 2-1 with a cross-section of other shapes, such as a trapezoidal or semicircular shape.

[0025] In this embodiment, the distance between any two adjacent grooves 2-1 is equal, and the distance between any two adjacent grooves 2-1 is 6-18 mm. The tab body forms a tooth portion 2-2 with a triangular cross section between any two adjacent grooves 2-1.

[0026] In this embodiment, the width of the tab body 2 is 4-20 mm, and the distance between the groove 2 - 1 and the coating area of ​​the pole piece 1 is greater than 0 and less than 20 mm.

[0027] It should be noted that when the tab structure of this embodiment is connected to the positive electrode sheet, the tab body 2 is made of aluminum foil with a thickness of 8-25 μm. When the tab structure of this embodiment is connected to the negative electrode sheet, the tab body 2 is made of copper foil with a thickness of 4-15 μm.

[0028] It should be noted that when the tab structure of this embodiment is connected to the positive electrode sheet, the width of the coating area of ​​the electrode sheet 1 is 110-300 mm. When the tab structure of this embodiment is connected to the negative electrode sheet, the width of the coating area of ​​the electrode sheet 1 is 113-303 mm.

[0029] It should be noted that when a component is referred to as being "mounted on" another component, it may be directly on the other component or there may be a central component. When a component is considered to be "set on" another component, it may be directly set on the other component or there may be a central component at the same time. When a component is considered to be "fixed to" another component, it may be directly fixed on the other component or there may be a central component at the same time.

[0030] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art in the technical field of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "or / and" used herein includes any and all combinations of one or more related listed items.

[0031] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0032] The above-mentioned embodiments only express several implementation methods of the utility model, and the description is relatively specific and detailed, but it cannot be understood as limiting the scope of the utility model patent. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the utility model, which all belong to the protection scope of the utility model. Therefore, the protection scope of the utility model patent shall be based on the attached claims.

Claims

1. A pole ear structure, located on a pole piece (1), characterized in that: It comprises a pole ear body (2), and a plurality of grooves (2-1) are arranged at intervals on one side of the pole ear body (2) away from the pole piece (1).

2. The tab structure according to claim 1, characterized in that: The groove (2-1) has a V-shaped, trapezoidal or arc-shaped cross section.

3. The tab structure according to claim 2, characterized in that: The groove (2-1) has a V-shaped cross section.

4. The tab structure according to claim 3, characterized in that: The distance between any two adjacent grooves (2-1) is equal and the distance between any two adjacent grooves (2-1) is 6-18 mm.

5. The tab structure according to claim 4, characterized in that: A tooth portion (2-2) is formed between any two adjacent grooves (2-1) on the tab body (2), and the tooth portion (2-2) has a triangular cross section.

6. The tab structure according to claim 4, characterized in that: The width of the tab body (2) is 4-20 mm.

7. The tab structure according to claim 6, characterized in that: The distance between the groove (2-1) and the coating area of ​​the pole piece (1) is greater than 0 and less than 20 mm.

8. The tab structure according to claim 1, characterized in that: The tab body (2) is made of aluminum foil with a thickness of 8-25 μm or copper foil with a thickness of 4-15 μm.

9. A pole piece (1), characterized in that: The electrode comprises the tab structure according to any one of claims 1 to 8.

10. A lithium battery, characterized in that: It comprises a pole piece (1) as claimed in claim 9.

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