Positive pole current collector of lithium ion battery

Abstract

The invention relates to a positive pole current collector of a lithium ion battery. The current collector is of a three-layer structure, wherein the first layer and the third layer are made of aluminum and have the thickness of 2.5-3 microns; the second layer arranged between the first layer and the third layer is an aluminum alloy layer and has the thickness of 8-10 microns; and the aluminum alloy comprises the following components in percentage by mass: 0.4-0.45 percent of Si, 0.4-0.45 percent of Fe, 0.06-0.08 percent of Cu, 0.5-0.6 percent of Mn, 0.05-0.08 percent of Ca, 0.01-0.015 percent of Sb, 0.1-0.15 percent of Ti-B alloy, 0.45-0.6 percent of RE, 15-20 percent of La, 55-60 percent of Ce, 10-15 percent of Er, 10-15 percent of Sm and the balance of aluminum and inevitable impurities, wherein RE refers to mixture rare earths. The preparation method comprises the following steps: smelting, performing homogenizing treatment, cold rolling and performing two-stage aging. According to the positive pole current collector disclosed by the invention, the tensile strength can be 260-275MPa, a corrosive pitting phenomenon is avoided, and compared with an aluminum foil in the prior art, the positive pole current collector has the advantage that problems of wrinkle and breakage can be effectively solved on the basis that a certain aluminum foil thickness is guaranteed.

Description

technical field [0001] The invention relates to an aluminum alloy material for a positive electrode collector of a lithium ion battery and a manufacturing method thereof, belonging to the field of lithium ion batteries. Background technique [0002] With the development of modern society and technology, mobile devices such as camcorders, notebook computers, portable DVDs and digital cameras have been used more and more widely. Lithium-ion battery, as a green battery, has the advantages of high energy density, high operating voltage and long service life, so it is widely used in various mobile devices. [0003] A lithium-ion battery generally includes a positive electrode sheet, a negative electrode sheet, a separator spaced between the positive electrode sheet and the negative electrode sheet, and an electrolyte. Wherein, the positive electrode sheet includes a positive electrode current collector made of aluminum foil and a positive electrode active material distributed on...

AI Technical Summary

Problems solved by technology

[0004] At present, as the thickness of aluminum foil is getting lower and lower, its overall strength is also reduced, resulting in aluminum foil being easy to wrinkle and break during the coating and cold pressing process, which affects normal production, so how to adjust the relationship between thickness and strength problem to be solved

There are attempts in the industry to use copper foil and nickel foil instead of aluminum foil as the positive electrode collector, but when copper foil and nickel foil are used in the positive electrode, they will be oxidized and then copper ions and nickel ions will dissolve into the battery; on the other hand, there are also problems in Alloying elements are added to aluminum foil to enhance its strength, but pitting corrosion will occur

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