A preparation method and product based on conductive carbon airgel composite nano-silicon negative electrode material

Abstract

The invention discloses a preparation method and product based on conductive carbon airgel composite nano-silicon negative electrode material. The preparation method comprises: (1) dissolving pretreated waste biomass and fiber additives in an aqueous solution of alkaline substances In the process, the reticular solid gel is obtained after stirring; (2) the reticular solid gel is dried, and then sieved to obtain the carbon airgel precursor; (3) the gaseous silicon source and carbon aerogel Colloid precursor is used as raw material, and the compound of carbon airgel and nano-silicon is prepared after chemical vapor deposition process; (4) The compound of carbon airgel and nano-silicon is blended with carbon source, and obtained after heating and carbonization Based on conductive carbon airgel composite nano-silicon anode material. The preparation method disclosed by the invention uses waste biomass as a raw material, has low cost, the prepared negative electrode material has high strength and good conductivity, and the assembled battery has high first effect.

Description

technical field [0001] The invention relates to the field of negative electrode materials for batteries, in particular to a preparation method and products thereof based on conductive carbon airgel composite nano-silicon negative electrode materials. Background technique [0002] Current state-of-the-art lithium-ion batteries are no longer sufficient to meet the growing demands of electric vehicles and large-scale energy batteries. Silicon is considered the most promising candidate to replace graphite. It is the second most abundant element in the earth's crust, is environmentally friendly, and has a super high theoretical capacity (4200mAh / g). However, during cycling, the volume of silicon particles rapidly expands and contracts with the intercalation and delamination of lithium ions (Li-ions). This drastic volume change leads to pulverization of silicon particles, destruction of silicon-based electrodes, and repeated regeneration of the solid electrolyte interfacial laye...

AI Technical Summary

Problems solved by technology

[0006] This technical scheme combines the high specific surface area of ​​carbon airgel and the excellent conductivity of graphene to prepare composite negative electrode materials. Airgel and nano-silicon liquid are mixed for hydrothermal reaction. Since the hydrothermal reaction is carried out under high temperature and high pressure, the gas and liquid raw materials are always in a boiling state, which will easily lead to the collapse of carbon aerogel, and is not conducive to the synthesis of silicon and carbon gas. compounding of gel

In addition, due to the evacuation of graphene properties, the CA / nano-silicon composite material cannot be well wrapped, and there is a risk of direct contact between silicon and electrolyte during charging and discharging, which will consume capacity and cause irreversible damage

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