Multi-tab lithium battery core and welding method of multi-tab lithium battery tab

Abstract

The invention discloses a welding method of a multi-tab lithium battery tab. The welding method comprises the following steps: (S1) sleeving a negative tab and a positive tab of a lithium battery core with a copper flat ring and an aluminum flat ring respectively; (S2) pre-pressing the core sleeved with the flat rings so as to firmly connect the flat rings with the core; (S3) arranging an electrode outgoing line on a battery top cover at the center position of a clip-shaped ring; and (S4) welding the center position in the (S3) so as to weld the tab pressed with the flat rings together with the outgoing line of the battery top cover. The invention also provides a battery core produced by the method. According to the welding method, the core tab is well welded together with the outgoing line of the battery top cover, so that the phenomena such as tab drop and insufficient welding can be avoided, and also the damage phenomenon of a foil tab in a welding process can be avoided.

Description

technical field [0001] The invention relates to the technical field of lithium battery production, in particular to a method for welding a multi-tab lithium battery winding core and its tabs. Background technique [0002] In recent years, people have been pursuing low-carbon life, and at the same time, traditional energy sources such as oil and coal have become less and less. As a clean, environmentally friendly, and low-carbon lithium battery, it has become an effective way to solve current environmental and energy problems. Attract people's attention. [0003] Electric public transportation is becoming more and more popular in some large and medium-sized cities, and green vehicles such as electric cars are gradually approaching the homes of ordinary people, and batteries provide power for these green transportation tools. The batteries used in these vehicles are basically lithium batteries and have relatively large capacities. We all know that while the battery provides ...

AI Technical Summary

Problems solved by technology

At present, the common method to reduce the internal resistance of the battery is to use multi-pole ear rolling cores or laminations; there are two methods for multi-pole ear rolling cores, one is to weld a certain size and number of copper sheets and Aluminum sheet, the other is to directly use the pole piece base material to cut out the tabs at the corresponding position by a certain method. The former method will make the battery capacity smaller under the same situation and the internal structure of the battery will appear thicker at the top and thinner at the bottom. The trapezoidal shape is not conducive to the production of batteries; the latter method is very flat after the core is made and the battery capacity in the effective volume is large, but the tabs made by this method are directly cut from the base material, and the base material The material is generally only a few or tens of millimeters, and it is easy to cause some tabs to break or be damaged during the welding process with the lead wire of the battery top cover, which will greatly reduce the electrical performance of the battery or scrap it.

Patent CN103500844A disclosed "cylindrical multi-tab lithium-ion battery and its preparation method" adopts energy storage welding to directly weld a plurality of tabs on the protruding platform (31), but due to energy storage welding It is easy to cause false welding and damage to the foil when the tab is used, which is not conducive to the actual operation of production

Patent CN202549967U discloses "a connection method between multi-pole tabs and cover plates of lithium-ion power batteries" in which one tab is welded to another tab and so on, which has solved the phenomenon of tab falling off and false welding. However, in actual production, it is more practical for batteries with fewer tabs, but for batteries with a large number of tabs, especially for batteries that directly use foil as tabs, this welding method is not feasible

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