Copper-nickel alloy foil and electro-deposition preparation method thereof

Abstract

The invention relates to a copper-nickel alloy foil and a preparation method thereof. A copper-nickel composite electrolyte system is adopted, and a specific complexing agent combination and an additive are selected according to electrodeposition characteristics of copper-nickel ions to form the copper-nickel alloy foil with the thickness of 3-10 mu m, wherein the mass fraction of nickel is 5.0-15.0%. Through testing, nickel crystal grains are uniformly doped in copper crystal grains, the maximum value of the surface roughness Rz of a rough surface is 2 mu m, the tensile strength is high and reaches 500 MPa or above, the elongation percentage is moderate, the wettability is suitable for a lithium battery current collector, the thickness is uniform, and edge tearing and belt breaking are avoided. The defects that a traditional pure copper double-sided plain foil is low in tensile strength, and edge tearing and belt breaking are extremely prone to occurring under the condition of thin thickness are overcome, and meanwhile, the problems that in a preparation process of the copper-nickel alloy foil, copper-nickel deposition is uneven, components of metal elements are difficult to control, the performance stability is poor, and the like are solved.

Description

technical field [0001] The invention relates to a copper-nickel alloy foil and an electrodeposition preparation method thereof, and further relates to a current collector material in a lithium battery. Background technique [0002] Double-sided light ultra-thin electrolytic copper foil is the key material for the negative electrode of high-quality lithium-ion secondary batteries. It affects the manufacturing process and comprehensive performance of lithium batteries. In recent years, with the rapid development of domestic new energy vehicles, lithium-ion batteries, as the power source of vehicles, are developing in the direction of smaller volume and larger capacity. This requires the negative electrode carrier copper foil of lithium-ion batteries to be thinner to carry more negative electrode materials. However, due to the low tensile strength of the traditional double-sided optoelectronic copper foil, it is easy to tear the edge during production and its downstream use. ...

AI Technical Summary

Problems solved by technology

This requires the negative electrode carrier copper foil of lithium-ion batteries to be thinner to carry more negative electrode materials. However, due to the low tensile strength of the traditional double-sided optoelectronic copper foil, it is easy to tear the edge during production and its downstream use. Problems of broken tape and low yield

[0003] Copper-nickel alloy is a new type of alloy material. Since copper-nickel can dissolve infinitely, copper-nickel alloy combines the characteristics of good corrosion resistance and high oxidation resistance of nickel and the characteristics of strong electrical conductivity of copper metal. At the same time, copper-nickel alloy Foil has excellent tensile strength and electrical conductivity, its tensile strength reaches above 500Mpa, electrical conductivity is close to that of pure copper, about 584000S / cm; and its thermal conductivity is excellent, it is an excellent collector material, but copper Nickel alloys have problems such as uneven distribution of copper and nickel elements and difficulty in controlling the composition during the electrodeposition process. Therefore, it is necessary to develop a copper foil with excellent performance and appropriate nickel content.