Battery cell with stepped tabs

Abstract

The utility model relates to the field of various battery cells needing ultrasonic welding actions, in particular to a battery cell applying stepped tabs, which comprises a battery cell body, the battery cell body comprises a plurality of stepped tabs and a pole piece body, the stepped tabs are distributed along the direction of the pole piece body, and the lengths of the plurality of stepped tabs extending out of the pole piece are sequentially increased at equal intervals. Welding areas are arranged on the plurality of stepped tabs, and the depths of the welding areas of the plurality of stepped tabs are gradually increased in sequence. According to the utility model, the tabs in the battery cell are the step-shaped tabs, the lengths of the plurality of step-shaped tabs extending out of the pole pieces are sequentially increased at equal intervals, and the depths of the welding areas of the plurality of step-shaped tabs are sequentially increased, so that the 100% welding area can be ensured during ultrasonic welding after winding, the overcurrent capability is ensured, and the temperature rise and the internal resistance are reduced; and the safety is ensured.

Description

Technical Field

[0001] This utility model relates to the field of battery cell technology that requires ultrasonic welding, and in particular to a battery cell using stepped tabs. Background Technology

[0002] The existing battery cells on the market typically have tabs of equal height on their internal electrode plates, forming a trapezoidal structure.

[0003] When ultrasonic welding is performed on these equal-height tabs after winding, the effective welding area becomes smaller as the tabs closer to the top are shaped. This ultimately leads to problems such as reduced current carrying capacity, excessive heat generation and temperature rise, and increased internal resistance in the battery cell. Furthermore, since the tabs inside the battery cell are of equal height, ultrasonic welding of such cells after winding will result in insufficient solder area, reduced current carrying capacity, increased temperature rise and increased internal resistance, posing safety hazards. Utility Model Content

[0004] The purpose of this invention is to address the shortcomings of existing technologies by proposing a battery cell with stepped tabs.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A battery cell using stepped tabs includes a battery cell body, the battery cell body including multiple stepped tabs and an electrode body, the stepped tabs being distributed along the direction of the electrode body, and the lengths of the multiple stepped tabs extending out of the electrode body increasing sequentially at equal distances, and each of the multiple stepped tabs having a welding area, the depth of the welding area of ​​the multiple stepped tabs increasing sequentially.

[0007] Furthermore, in a preferred configuration, the length of the plurality of electrode bodies is based on the shortest segment of the electrode body extending from the electrode body, and the remaining electrode bodies extend from the electrode body in a direction away from the shortest segment in an increasing sequence.

[0008] Furthermore, in a preferred configuration, the bottom lengths of the plurality of stepped tabs are all the same, and the bottom length of each stepped tab is 40mm.

[0009] The beneficial effects of this utility model are as follows:

[0010] In this invention, the tabs inside the battery cell are stepped tabs, and the lengths of multiple stepped tabs extending from the electrode sheet increase sequentially at equal distances. At the same time, the depth of the welding area of ​​multiple stepped tabs increases sequentially. After winding, ultrasonic welding can ensure 100% of the weld area, guaranteeing the current carrying capacity, reducing temperature rise and internal resistance, and ensuring safety. Attached Figure Description

[0011] Figure 1This is a schematic diagram of the stepped electrode structure;

[0012] Figure 2 This is a side view of the core after the stepped tabs are wound.

[0013] Figure 3 This is an illustration of the super-welding effect of a stepped electrode tab.

[0014] Figure 4 This is a schematic diagram of the structure of a medium-high electrode in the prior art;

[0015] Figure 5 A side view of the core after the high-precision lugs have been wound using existing technology;

[0016] Figure 6 This is an illustration of the effect of high-strength tab over-welding using existing technology.

[0017] In the diagram: 1. Electrode body; 2. Stepped electrode tab; 3. Welding area. Detailed Implementation

[0018] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments.

[0019] Reference Figure 1-6 A battery cell using stepped tabs includes a battery cell body, which includes multiple stepped tabs 2 and an electrode body 1. The stepped tabs 2 are distributed along the direction of the electrode body 1, and the lengths of the multiple stepped tabs 2 extending out of the electrode body increase sequentially at equal distances. Each of the multiple stepped tabs 2 is provided with a welding area 3, and the depth of the welding area 3 of the multiple stepped tabs 2 increases sequentially.

[0020] Furthermore, the length of the multiple electrode bodies 1 is based on the shortest segment of the electrode body 1 extending from the electrode, and the lengths of the remaining electrode bodies 1 extending from the electrode body 1 increase sequentially in the direction away from the shortest segment.

[0021] Meanwhile, the bottom lengths of multiple stepped tabs 2 are all the same, and the bottom length of each stepped tab 2 is 40mm.

[0022] In this embodiment, reference is made to Figure 6 After the tabs are shaped, the horizontal length of the tabs gradually decreases from the bottom upwards. Assuming the core thickness after hot pressing is H, and the pressing distance of the uppermost tab after shaping is h (the pressing distance h varies depending on the size of the shaping block), and the total offset in the horizontal length direction of the tabs is s, then:

[0023] s = (H / 2) - h

[0024] refer to Figure 3 Assume that the set of horizontal lengths of each layer of electrode is Sn (Sn is an arithmetic sequence with a common difference of q), the length of the electrode is L, and the total number of electrode layers is m:

[0025] q = s / (m-1)

[0026] Sn = L + s / (m-1) * (n-1)

[0027] In this utility model, the electrode inside the battery cell is a stepped electrode (2), and the length of the multiple stepped electrode (2) extending out of the electrode sheet increases sequentially at equal distances. At the same time, the depth of the welding area (3) of the multiple stepped electrode (2) increases sequentially. After winding, when ultrasonic welding is performed, the welding area can be guaranteed to be 100%, ensuring the current carrying capacity, reducing the temperature rise and internal resistance, and ensuring safety.

[0028] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. An electrode group using a stepped tab, comprising an electrode group body, characterized by, The battery cell body comprises a plurality of stepped tabs (2) and a tab body (1), the stepped tabs (2) are distributed along the direction of the tab body (1), the stepped tabs (2) are equidistantly and sequentially increased in length, and the plurality of stepped tabs (2) are provided with welding areas (3), and the depths of the welding areas (3) of the plurality of stepped tabs (2) are sequentially increased.

2. The battery cell of claim 1, wherein, The plurality of tab bodies (1) are sequentially increased in length along the direction away from the shortest section based on the length of the tab body (1) with the shortest tab length.

3. The battery cell of claim 1, wherein, The lengths of the bottoms of the plurality of stepped tabs (2) are uniform, and the length of the bottom of the stepped tab (2) is 40 mm.

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