Preparation method for silicon particle/graphene quantum dot core-shell structure

Abstract

The invention provides a preparation method for a silicon particle / graphene quantum dot core-shell structure. The method comprises the following steps: adding silicon particles to a small-lamella oxidized graphene solution of oxidized graphene quantum dots and graphene quantum dots in an approximate size, after ultrasonic-dispersing uniformly, continuously stirring, so as to obtain a silicon particle / oxidized graphene quantum dot core-shell structure; naturally airing, heating and removing a residual solvent, forming a silicon particle / wrinkle oxidized graphene structure, reducing to obtain the silicon particle / graphene quantum dot core-shell structure. The method is characterized in that by using the graphene quantum dots and the small size graphene, the silicon particles can be coated more easily, abundant wrinkle can be formed through overlapping of a large number of boundaries and slight twisting and rising of lamellae, wherein a wrinkle graphene coating layer has elasticity, can be compressed, and is capable of effectively buffering volume expansion of silicon. A contact area of the graphene quantum dot coating layer and the silicon particles is larger, so that charging and discharging can be more rapidly performed, energy consumption is low, control is easy, a synthetic process is simple, and a requirement to equipment is lower. The method is suitable for industrial or laboratory operation.

Description

technical field [0001] The invention relates to the field of preparation of electrode materials, in particular to a method for preparing a silicon particle / graphene quantum dot core-shell structure. Background technique [0002] The reserves of silicon in the earth's crust are very abundant, second only to oxygen. Silicon has high volume-specific capacity and mass-specific capacity, and its high lithium-deintercalation potential can effectively avoid the precipitation of lithium during high-rate charging and discharging, which can improve the safety of the battery and will not co-intercalate with the electrolyte. The scope of application of the electrolyte is wider, therefore, silicon is considered to be the most potential anode material for a new generation of high-capacity lithium-ion batteries. Silicon has serious volume expansion (~300%) during charge and discharge, and the silicon electrode material will be pulverized and peeled off from the current collector during ch...

AI Technical Summary

Problems solved by technology

However, the method for preparing hollow structures is complicated, requires precise control and takes a lot of time, and the corroded part forms a waste. A simpler and more effective method is urgently needed to solve the volume effect of silicon.

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