Preparation method of high-capacity anode material

Abstract

The invention relates to a preparation method of a high-capacity anode material, in particular to a method for synthesizing a high-capacity core-shell structure anode material for a lithium-ion battery. The method comprises the following steps: firstly, adding high-capacity nano-particles to raw materials of synthesizing mesocarbon microbeads, and carrying out high-speed stirring and high-temperature polymerization; with the high-capacity nano-particles as a core, generating the mesocarbon microbeads on the surface through polymerization of polycyclic aromatic molecules; and finally obtaining the high-capacity core-shell structure anode material with the high-capacity nano-particles as the core and the mesocarbon microbeads as the shell through high-temperature carbonization. Compared with a traditional synthesis process, the preparation method has the advantages ofachieving uniform coating, simple in process, excellent in electrochemical properties and the like.

Description

technical field [0001] The invention belongs to the field of lithium-ion battery materials, and mainly relates to a preparation method of a high-capacity negative electrode material for lithium-ion batteries. Background technique [0002] At present, the anode materials for commercial lithium-ion batteries are mainly graphite carbon, and the reversible specific capacity of carbon materials has reached 360mAh / g, which is close to its theoretical specific capacity of 372mAh / g. In order to further improve the energy density of lithium-ion batteries, new high-capacity anode materials have become a hot topic of related research. The alloy materials formed by Si, Sn, Al, etc. and Li have a reversible lithium storage capacity much higher than that of graphite negative electrodes. Among them, silicon and tin have high theoretical specific capacity, low lithium intercalation and extraction potential and low price. Advantages, become the focus and hotspot of lithium-ion battery resea...

AI Technical Summary

Problems solved by technology

However, the sample prepared by ball milling for 20 hours has a larger specific surface area due to the destruction of the structure of the mesophase carbon microspheres, which can form more SEI films, resulting in high irreversible capacity and low capacity retention.

It is difficult to embed Si and Sn into the internal structure of mesocarbon microspheres by using traditional methods such as ball milling to compound mesocarbon microspheres with Si and Sn, and it is difficult to greatly improve the performance of the composite material.

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