A hollow structure silicon-carbon composite electrode material and a preparation method thereof

Abstract

The invention discloses a hollow structure silicon-carbon composite electrode material and a preparation method thereof. The preparation method comprises the following steps: S1, dispersing nano silicon particles into an organic solvent, adding a coupling agent and adjusting the pH value to 3-4, washing and drying to obtain modified nano silicon particles; S2, respectively arrange an aqueous phasesolution and an oil phase solution, dispersing that modify nano-silicon particles of the step S1 into the oil phase solution, adding the modified nano-silicon particle into the aqueous phase solution, adding an initiator, centrifuging, washing, and drying to obtain a composite material coated with a layer of polymer on the nano-silicon particles; S3: adding the composite material of the step S2 into Tris buffer solution, adding dopamine hydrochloride, centrifuging, filtering, and drying to obtain the composite material coated with the double-layer polymer on the nano silicon particles; S4: The composite material of step S3 is carbonized to obtain a silicon-carbon composite electrode material. The invention has the advantages of simple process, environment friendliness, uniform polymer coating, stable structure, and excellent electrochemical performance of the prepared silicon-carbon composite electrode material.

Description

technical field [0001] The invention relates to the field of battery materials, in particular to a silicon-carbon composite electrode material with a hollow structure and a preparation method thereof. Background technique [0002] At present, the negative electrode materials of commercial lithium-ion batteries are mainly graphite materials. The theoretical specific capacity of graphite is only 372mAh / g, while the high-end graphite materials on the market have reached 360-365mAh / g, which is very close to its theoretical capacity and development potential. fairly limited. Facing the increasingly high performance requirements for lithium-ion batteries such as portable electronic devices and new energy vehicles, it is necessary to develop new lithium-ion battery anode materials. Due to the advantages of high theoretical capacity (about 4200mAh / g), low discharge potential, and abundant storage, silicon-based anode materials are considered to be the anode materials for next-gener...

AI Technical Summary

Problems solved by technology

However, the carbon coating method on the surface of silicon particles reported in the literature is prone to uneven carbon source coating, and the particles are easy to agglomerate; in addition, in order to prepare hollow structures, HF pickling process is usually required, which is harmful to the environment and the cost is high

Images