Rolled copper foil for lithium ion battery current collector and lithium ion battery

Abstract

Provided is a rolled copper foil for a lithium ion battery current collector, having good adhesion to a negative electrode active substance and good ultrasonic weldability to metal foil or a tab terminal. The rolled copper foil for a lithium ion battery current collector fulfills: residual oil content [mg / m<2>] + (60-degree glossiness in average rolling direction / 400) <= 2.5; and 200 <= 60-degreeglossiness in average rolling direction <= 600.

Description

technical field [0001] The invention relates to a rolled copper foil for a lithium ion battery current collector and a lithium ion battery. Background technique [0002] Lithium-ion batteries have the characteristics of high energy density and can obtain relatively high voltage, and are mostly used in small electronic devices such as notebook computers, camcorders, digital cameras, and mobile phones. In the future, it is also expected to be used as a power source for large-scale equipment such as electric vehicles and distributed power sources in general households. [0003] figure 1 is a schematic diagram of a lithium-ion battery stack configuration. The electrode body of a lithium ion battery generally has a stacked structure in which dozens of positive electrodes 11 , separators 12 and negative electrodes 13 are wound or laminated. Typically, the positive electrode consists of a positive electrode collector formed of aluminum foil and LiCoO 2 , LiNiO 2 and LiMn 2 o ...

AI Technical Summary

Problems solved by technology

However, if the active material is thickly coated, there may be concerns about the adhesion between the copper foil and the active material, such as peeling of the active material.

In addition, the use of Si-based active materials has been studied as another means for increasing the capacity of batteries, but the Si-based active materials may cause problems with adhesion due to higher expansion and shrinkage ratios than existing ones.

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