Preparation method of multilayer anode with porous carbon composite material

Abstract

The invention discloses a preparation method of a multilayer anode with a porous carbon composite material. According to the method provided by the invention, the activity of the material can be increased by utilizing porous carbon spheres with relatively large specific surface areas; a copper plated aluminum foil with a rough surface is selected in structure; the copper plated aluminum foil has the advantage of large specific surface area; through adoption of the relatively large specific surface area and a concave-convex structure, volume expansion of tin in a charge-discharge process can be buffered well; moreover, the structure plays a framework role; the volume expansion and shrinkage stress in the charge-discharge process can be buffered greatly; the first time charge-discharge efficiency of the anode material is 76%; when the anode material discharges in 400mA / g, after the anode material cycles for 360 cycles, the capacity retention ratio is 79%; and when the anode material discharges in 600mA / g, after the anode material cycles for 480 cycles, the capacity retention ratio is 88%. The method provided by the invention is simple in technology and easy in control and is applicable to large scale production.

Description

technical field [0001] The invention relates to a method for preparing a multilayer negative electrode with a porous carbon composite material. Background technique [0002] Lithium-ion batteries are mainly composed of casing, positive electrode, negative electrode, electrolyte and separator, and the negative electrode material is mainly carbon material. At present, there are three types of commercial lithium-ion battery anode materials: graphite-like carbon, graphitizable carbon (soft carbon), and amorphous carbon (hard carbon) materials. However, the theoretical specific capacity of graphite is only 372mAh / g, and the manufacturing cost is high. , poor safety performance; although soft carbon materials have a large number of turbostratic structures and heterogeneous atoms such as hydrogen, which make them have high specific capacity (generally 600-800mAh / g), but their voltage hysteresis is large, and the first Coulombic efficiency Low and fast attenuation, so the practical...

AI Technical Summary

Problems solved by technology

At present, there are three types of commercial lithium-ion battery anode materials: graphite-like carbon, graphitizable carbon (soft carbon), and amorphous carbon (hard carbon) materials. However, the theoretical specific capacity of graphite is only 372mAh / g, and the manufacturing cost is high. , poor safety performance; although soft carbon materials have a large number of turbostratic structures and heterogeneous atoms such as hydrogen, which make them have high specific capacity (generally 600-800mAh / g), but their voltage hysteresis is large, and the first Coulombic efficiency Low and fast attenuation, so the practical application is greatly limited; compared with soft carbon materials, hard carbon materials have a lower platform, the first efficiency and cycle life are improved, but the specific capacity is lower than soft carbon materials

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