All-tab lithium ion battery

Abstract

The utility model discloses a full-tab lithium ion battery, which comprises a winding pole group and a cover plate, a pin is connected onto the cover plate, the pole group is provided with tabs, the tabs are additionally provided with connecting parts, the connecting parts of the tabs are of a tiled and laminated structure, the pin is additionally provided with connecting parts, and the connecting parts of the tabs are of a tiled and laminated structure. And the pin is connected with the tab through the pin connecting part and the tab connecting part. According to the utility model, the connecting parts are additionally arranged on the pins and the tabs, so that the welding heat diffusion of the pins and the tabs can be reduced, the process yield is improved, and the product safety performance is improved; the welding thickness can be reduced, and the welding controllability is improved; the space utilization rate of the battery cell can be effectively improved. And meanwhile, the tab connecting part adopts a tiled laminated structure, so that the stress at the corner R of the tab can be released, the welding process of the pin and the tab is further easy to control, the process yield is favorably improved, and the product quality is favorably improved.

Description

Technical Field

[0001] The utility model relates to a lithium-ion battery, in particular to a full-tab lithium-ion battery. Background Art

[0002] Lithium batteries are widely used in many fields due to their outstanding characteristics such as high working voltage, large specific energy, and small self-discharge. With the rapid growth of new energy vehicles, the power battery industry has flourished. At present, the tabs of the wound core of square lithium-ion batteries are mainly divided into full tabs and multi-tabs. Full-tab batteries are widely used in power-type lithium-ion batteries because of their outstanding rate performance. The full-tab bipolar group lithium-ion battery has the advantages of low internal resistance and higher manufacturability, and has more advantages in application. However, when the full-tab pole group is ultrasonically welded to the cover pin / connecting piece, it is difficult to control during welding because of the large number of tab layers and large thickness. If the welding energy is too low, there will be a problem of false welding. The internal resistance of the falsely welded battery is large, and the risk of battery failure after formation is relatively high, and even internal short-circuit thermal runaway may be caused. If the welding energy is too high, there will be a risk of welding crack at the tab welding part. The positive connecting piece (pin) generally uses an aluminum connecting piece. With a large ultrasonic welding energy, there will be a phenomenon of sticking to the welding head, and even the connecting piece will be deformed, resulting in stress concentration and affecting the performance of the formed battery core. In addition, the full-tab bipolar group lithium-ion battery also has the problems of wider pin size on the battery cover and small volume utilization rate. Summary of the Utility Model

[0003] The utility model provides a lithium-ion battery that is convenient to control the welding quality between the tab and the pin to solve the technical problems existing in the known technology.

[0004] The technical solution adopted by the utility model to solve the technical problems existing in the known technology is: a full-tab lithium-ion battery, including a wound pole group and a cover plate. A pin is connected to the cover plate. The pole group is provided with tabs. The tabs are additionally provided with connecting parts. The tab connecting parts adopt a flat-laminated structure. The pin is additionally provided with a connecting part. The pin is connected to the tab through the pin connecting part and the tab connecting part.

[0005] The positive and negative pins are both formed by connecting two front and rear pins. The width direction of the pin is parallel to the length direction of the wound pole group. Each pin has left and right parts. The part far from the center line of the cover plate is the pin connecting part. The pin connecting part adopts a flat-laminated and bendable structure and bends inward after being welded to the tab connecting part.

[0006] The positive and negative pins are both independent single pins. The width direction of the pin is perpendicular to the length direction of the wound pole group. Most of both sides of the pin are provided with the pin connecting parts protruding outward. The tab connecting part bends inward and is welded to the pin connecting part.

[0007] The width of the tab connection part is the same as that of the wound electrode group.

[0008] The tab connection part is disposed in the middle, and its width is smaller than that of the wound electrode group.

[0009] The advantages and positive effects of the present utility model are as follows: By adding connection parts to the pins and tabs, the heat diffusion during the welding of the pins and tabs can be reduced, the process yield can be improved, and the product safety performance can be enhanced; the welding thickness can be reduced, and the weldability can be improved; the space utilization rate of the battery cell can be effectively increased. At the same time, the tab connection part adopts a flat-laminated structure, which can release the stress at the R corner of the tab, further facilitating the control of the welding process between the pin and the tab, being beneficial to improving the process yield, and being beneficial to improving the product quality. Description of the Drawings

[0010] Figure 1 is a schematic structural view of the first type of pin of the present utility model;

[0011] Figure 2 is Figure 1 a side view of;

[0012] Figure 3 is a schematic structural view of the second type of pin of the present utility model;

[0013] Figure 4 is Figure 3 a side view of;

[0014] Figure 5 is a schematic structural view of the first type of tab of the present utility model;

[0015] Figure 6 is Figure 5 a top view of;

[0016] Figure 7 is a schematic structural view of the second type of tab of the present utility model;

[0017] Figure 8 is Figure 7 a top view of;

[0018] Figure 9 is a schematic structural view of the second type of tab of the present utility model;

[0019] Figure 10 is Figure 9 a top view of;

[0020] Figure 11 is a schematic structural view of the welding of the first type of pin and the first type of tab of the present utility model;

[0021] Figure 12 is Figure 11 a left view of;

[0022] Figure 13 is Figure 11 the right view of

[0023] Figure 14 is the schematic diagram of the first welding structure between the pin and the second tab of the present utility model;

[0024] Figure 15 is Figure 14 the left view of

[0025] Figure 16 is Figure 14 the right view of

[0026] Figure 17 is the schematic diagram of the second welding structure between the pin and the second tab of the present utility model;

[0027] Figure 18 is Figure 17 the left view of

[0028] Figure 19 is Figure 17 the right view of

[0029] In the figure: 1. Cover plate; 1-1. Pin; 1-1-1. Pin connection part; 2. Wound electrode group; 2-1. Tab; 2-1-1. Tab connection part. Specific embodiments

[0030] In order to further understand the invention content, features and effects of the present utility model, the following embodiments are exemplified and described in detail with the accompanying drawings as follows:

[0031] Please refer to Figures 1 to 19 , a full-tab lithium-ion battery, comprising a wound electrode group 2 and a cover plate 1. A pin 1-1 is connected to the cover plate 1. The wound electrode group 2 is provided with a tab 2-1. The tab 2-1 is additionally provided with a connection part. The tab connection part 2-1-1 adopts a flat-laminated structure. The pin 1-1 is additionally provided with a connection part. The pin 1-1 is connected to the tab 2-1 through the pin connection part 1-1-1 and the tab connection part 2-1-1.

[0032] Please refer to Figures 1 to 2 and Figures 11 to 16 , the positive and negative pins are both formed by connecting two front and rear pins 1-1. The width direction of the pin 1-1 is parallel to the length direction of the wound electrode group 2. Each pin 1-1 has two left and right parts. The part far from the center line of the cover plate is the pin connection part 1-1-1. The pin connection part 1-1-1 adopts a flat-laminated and bendable structure and is bent inward after being welded to the tab connection part 2-1-1.

[0033] Please refer toFigures 3 to 4 , both the positive and negative electrode pins are independent pieces of the pin 1-1. The width direction of the pin 1-1 is perpendicular to the length direction of the wound electrode group 2. Most of both sides of the pin 1-1 are provided with the pin connection parts 1-1-1 protruding outward. The tab connection part 2-1-1 is bent inward and then welded to the pin connection part 1-1-1.

[0034] Please refer to Figures 5 to 6 , the width of the tab connection part 2-1-1 is the same as that of the wound electrode group 2. Before the electrode group is wound, the tab connection part is cut or die-cut. After cutting, full-tab winding is carried out, and there is no stress at the R corner of the tab connection part.

[0035] Please refer to Figures 7 to 8 and Figures 9 to 10 , the tab connection part 2-1-1 is centrally arranged, and its width is smaller than the width of the wound electrode group 2. Figures 7 to 8 Fig. shows a schematic diagram of forming the tab connection part 2-1 by cutting after the electrode group is wound; Figures 9 to 10 Fig. shows a schematic diagram of forming the tab connection part 2-1 by die-cutting after the electrode group is wound. After winding and forming, cutting or die-cutting can release the stress at the R corner of the tab connection part.

[0036] Please refer to Figures 11 to 13 , the schematic diagram of the welding structure of the first type of pin 1-1 and the first type of tab 2-1. The pin connection part 1-1-1 and the tab connection part 2-1-1 are first welded and then bent inward and attached to the end face of the electrode group.

[0037] Please refer to Figures 14 to 16 , the schematic diagram of the welding structure of the first type of pin 1-1 and the second type of tab 2-1. The pin connection part 1-1-1 and the tab connection part 2-1-1 are first welded and then bent inward and attached to the end face of the electrode group.

[0038] Please refer to Figures 17 to 19 , the schematic diagram of the welding structure of the second type of pin 1-1 and the second type of tab 2-1. Before welding, the tab connection part 2-1-1 is first bent inward and attached to the pin connection part 1-1-1, and then welding is carried out.

[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 above specific embodiments. The above specific embodiments are merely illustrative and not restrictive. Under the inspiration of the present invention, those of ordinary skill in the art can also make many forms without departing from the purpose of the present invention and the scope protected by the claims. All of these fall within the protection scope of the present invention.

Claims

1. A full-tab lithium-ion battery, comprising a wound electrode assembly and a cover plate, wherein pins are connected to the cover plate, and the electrode assembly is provided with tabs, and is characterized in that, The tab is additionally provided with a connecting part, and the tab connecting part adopts a flat laminating structure. The pin is additionally provided with a connecting part, and the pin is connected to the tab through the pin connecting part and the tab connecting part; The positive and negative pins are each formed by connecting two of the aforesaid pins. The width direction of the pin is parallel to the length direction of the wound electrode group. Each pin has left and right parts, and the part away from the center line of the cover plate is the pin connecting part. The pin connecting part adopts a flat laminating and bendable structure and bends inwards after being welded to the tab connecting part; The positive and negative pins are each an independent one of the aforesaid pins. The width direction of the pin is perpendicular to the length direction of the wound electrode group. Most of both sides of the pin are provided with the pin connecting parts protruding outwards; the tab connecting part bends inwards and is welded to the pin connecting part; The width of the tab connecting part is the same as that of the wound electrode group; The tab connecting part is arranged in the middle, and its width is smaller than the width of the wound electrode group.

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