Battery cell of coiled lithium ion battery

Abstract

The invention provides a battery cell of a coiled lithium ion battery. The battery cell is made by overlaying and winding two layers of pole pieces and two layers of diaphragms alternatively, whereineach pole piece comprises a pole piece body and a plurality of leads; the battery cell body is formed by coiling the pole piece bodies; an electrode is formed after the leads are overlaid in a staggered way; the total width of the electrode is D. Compared with the prior art, the battery cell has the beneficial effects that the leads are molded by coiling with a coiling needle after mold cutting, and different circles of leads are not aligned completely in a staggered way, so that the current carrying ability of the leads is ensured, and convenience can be brought to welding.

Description

technical field [0001] The invention belongs to the technical field of lithium ion batteries, and in particular relates to an electric core of a wound lithium ion battery. Background technique [0002] In recent years, the new energy industry dominated by lithium-ion batteries has developed rapidly. The manufacturing technology of lithium-ion batteries has gradually developed from the original circular winding and square lamination to the current square winding. When the square winding method is used to prepare, in order to provide energy density, the industry generally adopts multi-tab die-cutting for pole piece processing. When adopting this method, the method commonly used at this stage is to align the tabs, but in this way, during subsequent laser welding, high requirements are placed on the power control of the welding machine, and the power is too low to ensure that all tabs are aligned. Being welded will not only affect the flow capacity, but also cannot guarantee th...

AI Technical Summary

Problems solved by technology

When adopting this method, the method commonly used at this stage is to align the tabs, but in this way, during subsequent laser welding, high requirements are placed on the power control of the welding machine, and the power is too low to ensure that all tabs are aligned. Welding will not only affect the flow capacity, but also cannot guarantee the structural strength. If the power is too high, the tabs on the surface will be irreversibly damaged, reducing the yield of the battery.

Images