Lithium ion power cell with high power

Abstract

The invention discloses a high-power lithium ion power battery, comprising a plurality of single electrical cores connected in parallel. Each single electrical core consists of an anode plate, a cathode plate, a separator film, and two to eight anode tabs and cathode tabs. The anode tabs and the anode plate are integrated as a whole which is punched on the aluminum foil of the current collector of the anode; the cathode tabs and the cathode plate are integrated as a whole which is punched on the copper foil of the current collector of the cathode. All the tabs of the anodes of the single electrical cores are welded on a positive pole, while all the tabs of the cathodes are welded on a negative pole. By the structure of a variety of single electrical cores connected in parallel and a plurality of tabs integrated as a whole, the high-power lithium ion power battery leads the total essential resistances of the batteries to be further reduced and the currents of the anode and cathode plates to be distributed more uniformly, as a result, the high-power lithium ion power battery has the advantages of small essential resistances in total, high discharge rate, lower possibility of forming lithium dendrites, long cycle life and high specific power etc., and is widely used in electric vehicles, electric tools and other equipment in need of high-power batteries.

Description

technical field [0001] The invention relates to a lithium ion power battery, especially a high-power lithium ion power battery designed for use in electric vehicles and power tools. Background technique [0002] In the early 1990s, a new type of energy storage system, lithium-ion batteries, began to mature and enter the market. It is characterized by high capacity, long life and no pollution, but at that time, its expensive price and possible explosion The hidden dangers seriously limit its application in daily life, including the field of electric vehicles. After more than ten years of development, lithium-ion battery technology has made great progress, but there are still some technical problems that have not been completely solved. Therefore, about 90% of electric vehicles in the country are still in use, which pollutes the environment, has short lifespan, and has high energy consumption. Low-density lead-acid batteries. [0003] In recent years, more and more technical...

AI Technical Summary

Problems solved by technology

[0002] In the early 1990s, a new type of energy storage system—lithium-ion batteries began to mature and entered the market. It was characterized by high capacity, long life, and no pollution. However, at that time, its high price and possible explosion Hidden dangers severely limit its range of applications in daily life, including the field of electric vehicles

[0005] For winding high-power batteries, because the thickness of the tabs and the tab tape is generally greater than the thickness of the electrode material coating, the positive and negative electrodes around the tabs cannot be in good contact and the position of the tabs in the battery core is not good. Drums, which affect the uniformity and stability of the pole piece, and then affect the life of the battery; this structure will also cause the coating of one pole tab to face the other pole, making it easy to form lithium in the gap around the negative pole tab. Dendrites affect safety, the more the number of tabs welded to the pole piece, the more serious the above problems

In response to this problem, some people have adopted a method of shortening the overlapping length of tabs and pole pieces in cylindrical batteries and compacting the overlap between tabs and pole pieces with external force to reduce the height difference. The overlapping of pole pieces is in conflict with the welding area and thicker tabs. This method can achieve limited results in the field of high-rate power batteries, and it cannot completely solve the problem of local swelling of the battery cell caused by the thickness of the tabs.

[0006] For the laminated high-power battery, there is no problem of uniformity of the pole piece caused by the tab of the wound battery, and there is no problem of local swelling of the battery cell caused by the tab, but each battery has 40-100 pairs of poles. The sheet cutting process, weight control process, diaphragm packaging negative electrode sheet process, and the final battery stack welding process are cumbersome and the workload is heavy, and its product rate is much higher than that of wound batteries

In addition, too many tabs are also a great challenge for the welding of tabs and poles

[0007] In addition to the above-mentioned improvements, there is also a method of connecting cells welded with a single tab in parallel to form a battery, which simplifies the production difficulty to a certain extent and increases the total number of tabs, but it still cannot completely get rid of the multi-tab winding battery. all the problems

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