High-magnification full-tab lithium ion battery cover plate with square aluminum shell winding structure

Abstract

The utility model discloses a high-magnification full-tab lithium ion battery cover plate with a square aluminum shell winding structure, which comprises a cover plate main body, at least one group of positive pins and at least one group of negative pins are respectively arranged below two ends of the cover plate main body, each group of pins consists of a front pin and a rear pin, one pin is a welding protection sheet, and the other pin is a welding protection sheet. And the coil core is arranged in front of the coil core. According to the utility model, the pins used as the welding protection sheets are additionally arranged in front of the tabs, and the roll core tabs are inserted into the gaps of the pins for welding after being folded and subjected to ultrasonic pre-welding, so that the welding positioning accuracy and the stability of the connection between the roll core and the cover plate are improved; and more importantly, adhesion or tab welding cracks caused by direct contact between the welding head and the roll core tab in the welding process can be avoided, and the process qualification rate can be improved. And meanwhile, the front pin can bear partial overcurrent, so that compared with a single-pin structure, the overcurrent area is larger, the overcurrent temperature rise can be reduced, and the safety during large-current charging and discharging can be improved.

Description

Technical Field

[0001] This utility model relates to the field of lithium-ion battery manufacturing technology, and in particular to a high-rate full-tab lithium-ion battery cover. Background Technology

[0002] Lithium-ion batteries with an all-tab structure are well-suited for high-rate, high-current pulse applications due to their strong overcurrent capacity and low temperature rise during high-current charging and discharging. Existing cover plates for all-tab lithium-ion batteries often feature upright leads. These leads are typically single-strip structures, resulting in limited contact area between the tabs and leads, limiting overcurrent capacity, and causing unstable connections to the core. Under external force, they can easily detach from the core, affecting battery safety. Multi-strip lead cover plates typically involve first placing the core's tabs onto the cover's leads using a positioning fixture or robotic arm, then applying pressure with an ultrasonic welding machine's welding head directly to the tabs. This welding method is prone to cracking of the outer core tabs or adhesion between the outer tabs and the welding head, leading to low production yield. Furthermore, metal shavings generated during ultrasonic welding can enter the core and cause micro-short circuits, affecting battery self-discharge consistency and safety. Utility Model Content

[0003] This utility model provides a high-rate full-tab lithium-ion battery cover plate to solve the technical problems existing in the prior art. The cover plate is equipped with a welding protection sheet, which can prevent the welding head from directly contacting the core tab during the welding process, thereby preventing the outer tab from sticking to the welding head or the tab from cracking, and improving the process qualification rate.

[0004] The technical solution adopted by this utility model to solve the technical problems existing in the prior art is: a square aluminum shell wound structure high-rate full-tab lithium-ion battery cover plate, including a cover plate body, with positive electrode pins and negative electrode pins respectively provided at both ends of the cover plate body. The positive electrode pins and the negative electrode pins each include at least one set, and each set of pins consists of two pins, one of which is a welding protective sheet located in front of the core tab.

[0005] This full-tab lithium-ion battery cover is a single-core full-tab lithium-ion battery cover, with a set of positive electrode pins and a set of negative electrode pins, one of which is a welding protective sheet located in front of the core electrode tab.

[0006] The full-tab lithium-ion battery cover is a double-core or quadruple-core full-tab lithium-ion battery cover, with 2 sets of positive electrode pins and 2 sets of negative electrode pins. The negative electrode pins and positive electrode pins located on the outer side are welded protective sheets located in front of the core tabs.

[0007] The two negative pins located on the inside are rigidly connected at the bottom; the two positive pins located on the inside are rigidly connected at the bottom.

[0008] The thickness of the two inner negative pins is greater than the thickness of the two outer negative pins, and the thickness of the two inner positive pins is greater than the thickness of the two outer positive pins.

[0009] The width of the positive electrode pin is 3-10 mm, the thickness of the positive electrode pin on the outer side is 0.2-1 mm, and the thickness of the positive electrode pin on the inner side is 1-2 mm.

[0010] The width of the negative electrode pin is 3 to 10 mm, the thickness of the negative electrode pin on the outer side is 0.1 to 0.8 mm, and the thickness of the negative electrode pin on the inner side is 1 to 1.8 mm.

[0011] The advantages and positive effects of this invention are as follows: By adding a pin as a welding protection plate in front of the tab, the core tab is pre-positioned by inserting it into the gap of the pin after being gathered and ultrasonically pre-welded, and then undergoes final ultrasonic welding. This not only helps improve the welding positioning accuracy and the stability of the connection between the core and the cover plate, but more importantly, it avoids direct contact between the welding head and the core tab during welding, preventing adhesion or tab weld cracking, thus improving the process yield. Simultaneously, compared to the single-pin structure, current is mainly handled through the pin behind the tab, while the pin in front acts as a welding protection plate and also bears part of the current, resulting in higher compatibility, better structural stability, and a larger current-carrying area. This reduces overcurrent temperature rise and improves safety during high-current charging and discharging. In summary, this invention, through optimized design of the pins on the full-tab cover plate of the wound structure, not only reduces the risk of tab weld cracking and adhesion between the tab and the welding head during welding, but also effectively improves the pin's current-carrying capacity and reduces overcurrent temperature rise. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the structure of Embodiment 1 of the present utility model;

[0013] Figure 2 for Figure 1 The left view;

[0014] Figure 3 for Figure 1 The right view;

[0015] Figure 4 This is a schematic diagram of the structure of Embodiment 2 of the present invention;

[0016] Figure 5 for Figure 4 The left view;

[0017] Figure 6 for Figure 4 The right view;

[0018] Figure 7 A schematic diagram of the structure of a full-tab lithium-ion battery core;

[0019] Figure 8 This is a schematic diagram of the structure of Embodiment 2 of this utility model after welding with the double core;

[0020] Figure 9 for Figure 8 The right view;

[0021] Figure 10 This is a schematic diagram of the structure of Embodiment 2 of this utility model after welding with four core coils;

[0022] Figure 11 for Figure 10 The right view;

[0023] Figure 12 This is a schematic diagram of the structure of Embodiment 1 of this utility model after welding with a single core;

[0024] Figure 13 for Figure 12 The right view;

[0025] Figure 14 This is a schematic diagram showing the configuration of a full-pole lug cover plate ultrasonically welded to two core coils, wrapped with an insulating film, and then installed in an aluminum shell. Detailed Implementation

[0026] To further understand the invention content, features, and effects of this utility model, the following embodiments are provided, and detailed descriptions are given below in conjunction with the accompanying drawings:

[0027] Please see Figures 1 to 13 A high-rate, all-tab lithium-ion battery cover with a square aluminum shell and a wound structure includes a cover body 108. Positive and negative electrode leads are respectively provided at both ends of the cover body 108. Each positive and negative electrode lead consists of at least one set, with each set consisting of two leads, one of which is a welding protective sheet located in front of the wound electrode tab. A positive electrode pressure plate 106 and a negative electrode pressure plate 105 are provided on the top of the cover body 108.

[0028] Example 1:

[0029] Please see Figures 4-6A high-rate, full-tab lithium-ion battery cover with a square aluminum shell, single-core wound structure, is disclosed. This cover features a set of positive electrode leads 101 and 102 and a set of negative electrode leads 103 and 104, with any one of these leads serving as a welding protective sheet located in front of the core's tabs. The bottoms of the two leads in the same set are not connected. For cores of varying thicknesses, applying welding pressure with the welding head ensures tight contact between the two leads and the core.

[0030] Example 2:

[0031] Please see Figures 1-3 A square aluminum shell high-rate full-tab lithium-ion battery cover with single-core, dual-core, or quad-core wound structure. The full-tab lithium-ion battery cover is a dual-core or quad-core full-tab lithium-ion battery cover with two sets of positive electrode pins 101 and 102 and two sets of negative electrode pins 103 and 104. The negative electrode pins and positive electrode pins located on the outer side are welded protective sheets located in front of the core tabs.

[0032] The two inner negative electrode pins are rigidly connected at their bottoms; the two inner positive electrode pins are also rigidly connected at their bottoms, which improves the stability and torsional resistance of the cover plate structure. The two outer pins are not connected to the bottoms of the two inner pins. For cores of different thicknesses, after applying welding pressure with the welding head, it ensures that all four pins are in close contact with the core, preventing incomplete soldering and allowing compatibility with electrode tabs of different thicknesses. The thickness of the two inner negative electrode pins is greater than that of the two outer negative electrode pins, and the thickness of the two inner positive electrode pins is greater than that of the two outer positive electrode pins. More specifically, the width of positive electrode pins 101 and 102 is 3–10 mm, the thickness of the outer positive electrode pin is 0.2–1 mm, and the thickness of the inner positive electrode pin is 1–2 mm; the width of negative electrode pins 103 and 104 is 3–10 mm, the thickness of the outer negative electrode pin is 0.1–0.8 mm, and the thickness of the inner negative electrode pin is 1–1.8 mm. The thickness and width of the pins can be flexibly adjusted to meet different current carrying capacity requirements.

[0033] Applications of this utility model:

[0034] Please see Figure 7 , Figure 7 The diagram shows the structure of a full-tab lithium-ion battery core. The outermost layer of the core is the separator 201, the middle part is the tape 202 at the end of the separator cut, the left side is the aluminum positive tab 203, and the right side is the copper negative tab 204.

[0035] Please see Figures 8-9The diagram above illustrates the welding of the two full-tab cores in Embodiment 2. After the two full-tab cores 301 are wound, their positive and negative tabs in the same direction are die-cut and shaped to avoid positional interference between the tabs on both sides of the core and the insulating pad 107 of the cover plate. Then, the positive tab is clamped between a set of pins at the positive end of the cover plate, and the ultrasonic welding head is pressed onto the outer pins for connection. Welding typically produces a weld spot 302. Similarly, the negative tab is clamped between a set of pins at the negative end of the cover plate and then connected by ultrasonic welding. Welding typically produces a weld spot 303. After completion, the cover plate is rotated 180 degrees, and ultrasonic welding of the other full-tab core is completed. After ensuring the core surface is flat and that the thickness and width are normal, an insulating film 4 is wrapped around the surface, and the core is then inserted into the aluminum shell 5 to complete the full-tab battery assembly. Please refer to [link to documentation]. Figure 14 .

[0036] Please see Figures 10-11 The above-described embodiment 2, after being welded with four cores, differs from the double core in that two tabs are provided between a set of pins, while the rest are the same.

[0037] Please see Figures 12-13 The above embodiment 1 is a schematic diagram after welding with a single core. One full-tab core 301 is provided with a positive tab and a negative tab. The positive tab is clamped between two pins at the positive end of the cover plate, and the negative tab is clamped between two pins at the negative end of the cover plate. The welding and subsequent processing methods are the same as those of the above dual-core battery, and will not be described again here.

[0038] In summary, this invention, by adjusting the pin design of the full-tab cover plate suitable for wound cores, avoids direct contact between the welding head and the tabs during welding, thus preventing the tabs from sticking to the welding head or cracking during welding. Simultaneously, it increases the current-carrying capacity of the pins, reducing temperature rise during overcurrent. Furthermore, the adjusted pin structure is compatible with single-core, dual-core, and quad-core batteries. During welding, the pressure between the welding head and the welding base ensures that tabs of different thicknesses can make tight contact with each pin, achieving excellent welding results.

[0039] Although the preferred embodiments of the present invention have been described above in conjunction with the accompanying drawings, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present invention without departing from the spirit and scope of the claims, and these all fall within the protection scope of the present invention.

Claims

1. A square aluminum shell winding structure high rate full tab lithium ion battery cover plate, comprising a cover plate body, a positive electrode pin and a negative electrode pin are respectively arranged below both ends of the cover plate body, characterized in that The positive electrode pin and the negative electrode pin both contain at least one group, and a group of pins is composed of two front and back pins, one of which is a welding protection piece located in front of the winding core tab.

2. The square aluminum can wound structure high- rate capability full-tab lithium-ion battery cover plate of claim 1, wherein, The full tab lithium ion battery cover plate is a single winding core full tab lithium ion battery cover plate, which is provided with a group of positive electrode pins and a group of negative electrode pins, any one of which is a welding protection piece located in front of the winding core tab.

3. The square aluminum can wound structure high- rate capability full-tab lithium-ion battery cover plate of claim 1, wherein, The full tab lithium ion battery cover plate is a double winding core or four winding core full tab lithium ion battery cover plate, which is provided with two groups of positive electrode pins and two groups of negative electrode pins, wherein the negative electrode pins located on the outer side and the positive electrode pins located on the outer side are welding protection pieces located in front of the winding core tab.

4. The square aluminum can wound structure high-areal-density full-tab lithium-ion battery cover plate of claim 3, wherein, The bottom of the two negative electrode pins located on the inner side is rigidly connected; the bottom of the two positive electrode pins located on the inner side is rigidly connected.

5. The square aluminum can wound structure high-areal-density full-tab lithium-ion battery cover plate of claim 4, wherein, The thickness of the two negative electrode pins located on the inner side is greater than that of the two negative electrode pins located on the outer side, and the thickness of the two positive electrode pins located on the inner side is greater than that of the two positive electrode pins located on the outer side.

6. The square aluminum can wound structure high-areal-density full-tab lithium-ion battery cover plate of claim 5, wherein, The positive electrode pin width is 3-10 mm, the positive electrode pin thickness on the outer side is 0.2-1 mm, and the positive electrode pin thickness on the inner side is 1-2 mm; The negative electrode pin width is 3-10 mm, the negative electrode pin thickness on the outer side is 0.1-0.8 mm, and the negative electrode pin thickness on the inner side is 1-1.8 mm.

Images