Ferroferric oxide/silicon oxide/multilayer graphene composite material and preparation method thereof

Abstract

The invention discloses a ferroferric oxide / silicon oxide / multilayer graphene composite material and a preparation method. Multilayer graphene in the composite material is a carbon substrate material,is obtained by mechanical stripping of expanded graphite, has a thickness of less than 10nm, and has a flat surface. The ferroferric oxide and the silicon oxide form a composite film on the surface of the multilayer graphene, the ferroferric oxide and the silicon oxide are mutually isolated and uniformly distributed in the composite film, and the thickness of the film layer is less than 10nm. Thespecific preparation process of the ferroferric oxide / silicon oxide / multilayer graphene composite material comprises the following steps: putting expanded graphite into a mixed solution of DMF and water, and carrying out mechanical stripping to obtain a multilayer graphene dispersion liquid; weighing anhydrous sodium acetate, ferrous chloride and tetraethoxysilane, and adding the multilayer graphene dispersion liquid; putting into a water bath, stirring, and heating to 90 DEG C for 15 minutes at room temperature in the water bath; after reacting for a certain time, taking out, and centrifugally cleaning to obtain the ferroferric oxide / silicon oxide / multilayer graphene composite material. The preparation process is simple and suitable for industrial production.

Description

technical field [0001] The invention belongs to the technical field of materials, and relates to a ferric oxide / silicon oxide / multilayer graphene composite material and a preparation method thereof. The material of the invention has potential applications in the fields of catalysis, energy storage and the like, and can be used as a negative electrode material of a high-performance lithium ion battery. Background technique [0002] With the continuous development of portable electronic products, people have higher and higher requirements on the energy density, power density, service life and fast charging and discharging of energy storage devices. At present, the anode materials in commercial lithium-ion batteries are mainly graphite materials (theoretical capacity 372 mAh / g), and transition metal oxides have been widely recognized for their advantages such as high reversible capacity, low working voltage, abundant reserves, and no pollution to the environment. widespread at...

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Problems solved by technology

[0003] The theoretical capacity of ferroferric oxide is as high as (theoretical capacity 926mAh / g), but when ferric ferric oxide is charged and discharged, a huge volume expansion will occur, and after many cycles, the active material is easy to pulverize / fall off, resulting in Reduced cycle performance and rapid capacity decay

The nano-silica coating method is to prepare spherical silica particles first, and then coat metal oxides. The process is more complicated and not suitable for industrial production.

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