Preparation method of silicon-based/graphene composite

Abstract

The invention belongs to the technical field of new materials for a lithium ion battery, and particularly relates to a preparation method of a silicon-based / graphene composite. The preparation method comprises the following steps of: taking a pole of the silicon-based / graphene composite as a working electrode and the pole of a lithium source-containing material as a counter electrode, assembling a battery together with propylene carbonate and lithium salt-containing electrolyte and a diaphragm; charging and discharging the battery to co-embed lithium ions and carbonate propylene ester into graphite layers under the action of electric field, so as to enable the graphite layers to be stripped; dismantling the battery, placing a lithium-embedded silicon-based / graphene composite precursor into dimethyl carbonate solution for soaking, and vaccumizing and drying; and conducting ultrasonic cleaning and lithium removal in diluted hydrochloric acid, vacuumizing and filtering, drying, and burning under inert gas atmosphere. Compared with the prior art, the preparation method is simple and controllable in procedures, low in cost, safe and environment-friendly and incapable of causing environment and health security risk; and a great deal of hydrogen can also be collected in the preparation process of the composite, so that economic benefits are obvious.

Description

technical field [0001] The invention belongs to the technical field of new lithium-ion battery materials, and in particular relates to a method for preparing a silicon-based / graphene composite material. Background technique [0002] With the diversification of functions of consumer electronic products, lithium-ion batteries are used as the energy supply of electronic products, and their capacity and service life have begun to attract people's attention. However, there is often limited space for lithium-ion batteries in the design of electronic products. Increasing battery capacity, or more precisely, increasing the energy density of batteries is a key means for lithium-ion battery manufacturers to improve their competitiveness. To increase the energy density of the battery, we can start from increasing the gram capacity of the positive electrode material or the gram capacity of the negative electrode material, but the increase in the gram capacity of the positive electrode m...

AI Technical Summary

Problems solved by technology

[0011] The purpose of the present invention is to: aim at the deficiencies of the prior art, and provide a kind of preparation method of silicon-based / graphene composite material with simple procedure, low cost and safety and environmental protection, this method makes silicon-based / graphene composite material negative plate And assembled into a battery, directly under the action of an electric field, propylene carbonate (PC) is embedded between the graphite layers, so that the graphite layers are peeled off, and a high-capacity silicon-based / graphene composite material is obtained to overcome the preparation of silicon-based / graphene in the prior art. The method of graphene composite materials has complex procedures, high cost and potential environmental health and safety risks.

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