A kind of current collector of lithium ion battery and preparation method thereof

Abstract

The invention discloses a lithium-ion battery current collector and a preparation method thereof, relating to the field of lithium-ion batteries, including a metal foil, a first material layer, a second material layer, a third material layer, a fourth material layer, and a fifth material layer and a sixth material layer, the first material layer covers the upper surface of the metal foil, the second material layer covers the lower surface of the metal foil, and the third material layer covers the first The upper surface of the material layer, the fourth material layer covers the lower surface of the second material layer, the fifth material layer covers the upper surface of the third material layer, and the sixth material layer covers the the lower surface of the fourth material layer. The lithium-ion battery current collector proposed by the present invention has the characteristics of low contact resistance and high bonding strength, which effectively improves the cycle performance of the lithium-ion battery. safety performance.

Description

technical field [0001] The invention relates to the field of lithium ion batteries, in particular to a lithium ion battery current collector and a preparation method thereof. Background technique [0002] Since Sony commercialized lithium-ion batteries in 1990, lithium-ion batteries have developed rapidly, and their energy density, cycle life, and safety performance have been significantly improved, and the market size is increasing. It is expected that the global lithium-ion battery market will exceed 200 billion Wh, the average annual compound growth rate is close to 25%. [0003] As the market's requirements for the performance of lithium-ion batteries are getting higher and higher, the energy density, cycle life and safety issues of lithium-ion batteries have always been the technical direction that people are striving to improve. In the field of electric vehicles, the energy density of lithium-ion batteries affects the cruising range of the car, and the cycle life of l...

AI Technical Summary

Problems solved by technology

[0004] In order to improve the energy density of lithium-ion batteries, people have developed nickel-cobalt lithium manganate ternary cathode materials, but the safety performance of this type of material is not good; in order to improve the safety performance of batteries, there are many methods including external thermistors , electrolyte stabilizers and anti-overcharge additives, etc., but these methods have limited effects; in order to improve the cycle life of lithium-ion batteries, carbon-coated aluminum foil has become a research hotspot in recent years, but the function of carbon-coated aluminum foil is single, which is harmful to the safety performance of lithium-ion batteries. no substantive help

In recent years, the technology of compounding the material layer with the positive temperature effect of resistance on the positive and negative current collectors of lithium-ion batteries has emerged to improve the safety performance of lithium-ion batteries, but the defect of this technology is that it has the positive temperature effect of resistance. The bonding force between the material layer and the positive and negative current collectors and the positive and negative materials of the lithium-ion battery is not good, which affects the electrical performance of the lithium-ion battery

[0005] Therefore, those skilled in the art are committed to developing a lithium-ion battery current collector and its preparation method to overcome the shortcomings of energy density, safety performance and cycle life that cannot be taken into account in lithium-ion batteries of the prior art.

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