Composite lithium-ion battery cell with low internal resistance, and preparation technology thereof

Abstract

The invention provides a composite lithium-ion battery cell with low internal resistance, and a preparation technology of the composite lithium-ion battery cell, aiming at overcoming the defects. The battery cell internally comprises at least two single winding cells which are respectively provided with a positive pole lug and a negative pole lug; the pole lugs with the same polarity of the single winding cells are welded to form a whole body in a way of ultrasonic welding, so that the composite battery cell can be formed; the pole lugs of a positive pole piece and a negative pole piece of each single winding cell are arranged in the middle. After the composite lithium-ion battery cell is adopted, the internal resistance of a battery is effectively reduced under the condition that the battery capacity is not changed, so that the multiplying performance of the battery is improved, and the safety of the battery is improved.

Description

technical field [0001] The invention belongs to the field of lithium-ion batteries, and in particular relates to a low-internal-resistance composite lithium-ion battery cell with a structure of pole pieces placed in tabs, which reduces the internal resistance of the lithium-ion battery and improves safety, and a manufacturing process thereof. Background technique [0002] Lithium-ion batteries are widely used in various 3C products due to their advantages of high output voltage, high energy density, stable discharge voltage, and long cycle life. At the same time, with the advantages of high output power and long service life, the application of lithium-ion batteries has also extended from the communication industry to the fields of electric tools, large energy storage and power batteries. Power batteries are one of the main development directions of lithium-ion batteries, which requires them to have better rate performance and higher power and energy density. At the same ti...

AI Technical Summary

Problems solved by technology

For lithium-ion batteries using the winding process, too long pole pieces will bring unnecessary troubles to the manufacturing process, which will increase the defective rate of the product, and the internal resistance of the battery with long pole pieces is large, which is not conducive to the high current of the battery Charging and discharging seriously hinder the development of batteries in the direction of large capacity and high power

However, the pole piece of the existing winding lithium ion battery adopts the structure that the tab is arranged at one end of the pole piece. Since the tab is generally arranged inside the battery cell, the internal resistance is large and the heat dissipation is poor, which will cause the internal temperature of the battery to rise sharply. There are certain safety hazards in the battery

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