Multilayer structure current collector and preparation method thereof

Abstract

The invention relates to a multi-layer structure current collector and a preparation method thereof, the multi-layer structure current collector comprises a polymer film layer, two opposite surfaces of the polymer film layer are respectively provided with laminated layers, and each laminated layer comprises a carbon coating and a metal coating which are alternately laminated. According to the invention, the carbon coatings and the metal coatings are alternately arranged on the two opposite surfaces of the polymer film layer, so that the evaporation times of the metal coatings and the polymer film layer can be effectively reduced, the porosity and sheet resistance of a product can be effectively reduced, and the battery performance is effectively ensured; the attenuation of the mechanical property of the polymer film layer can be reduced, so that the attenuation of the mechanical property of the product is reduced; meanwhile, the carbon coating has excellent electrical conductivity and high mechanical property and chemical stability, so that the mechanical property, the electrical conductivity and the corrosion resistance of the product can be effectively improved; the carbon coatings are arranged on the two opposite surfaces of the polymer film layer, so that the polymer film layer can be protected.

Description

technical field [0001] The present invention relates to the technical field of secondary batteries, in particular to a multi-layer structure current collector and a preparation method thereof. Background technique [0002] The current current collectors are mainly copper current collectors and aluminum current collectors, wherein copper current collectors or aluminum current collectors are composed of two parts, including a polymer film layer arranged in the middle and a polymer film layer arranged opposite to the polymer film layer. Metal plating on both surfaces. The current collector is prepared by a vacuum evaporation process, but the thickness of the initial evaporation layer in the current evaporation process is between 32nm and 500nm, but with the increase of the number of metal layers, the thickness of the metal layer of each subsequent layer The increment is getting smaller and smaller. To achieve the set number of layers, it may take 15-20 consecutive evaporations...

AI Technical Summary

Problems solved by technology

The method of preparing the current collector is completed by vacuum evaporation process, but because the initial evaporation coating thickness of the current evaporation process is between 32nm-500nm, but with the increase of the number of metal coating layers, the thickness of the metal coating layer of each subsequent layer The increment is getting smaller and smaller. To reach the set number of layers, the polymer film layer may need to be evaporated continuously for 15-20 times to achieve the required thickness requirement. After repeated evaporation of the metal coating layer, there are many internal deposits. The porosity of the metal coating leads to a porosity of up to 30%. The existence of these pores reduces the flow area of ​​the metal coating and affects the transmission of electrons, resulting in a large square resistance inside the metal coating, increasing the polarization of the battery, and seriously Affect the performance of the battery. At the same time, after multiple evaporations, the polymer film layer in the middle has experienced dozens of sudden cooling and heat, which leads to the rapid decay of the mechanical properties of the polymer film layer, which leads to the tensile strength of the multilayer structure current collector. and elongation have relatively large attenuation

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