Three-dimensional composite material formed by filling carbon-encapsulated tin granules into graphene interlaminations and by filling graphene layers with carbon-encapsulated tin granules and preparation method for three-dimensional composite material

Abstract

The invention discloses a three-dimensional composite material formed by filling graphene layers with carbon-encapsulated tin granules and a preparation method for the three-dimensional composite material. The material is formed by uniformly filling the graphene layers with the carbon-encapsulated tin granules to form a three-dimensional sandwich-shaped structure; the preparation process is as follows: taking NaCl as a dispersing agent and a template, fully dissolving and mixing the NaCl with a metal source and a carbon source, freezing, drying and porphyrizing to obtain a mixture; putting the mixture into a tube furnace, and calcining under the argon protection to obtain a calcined product; and washing the calcined product, then mixing with glucosum anhydricum for hydrothermal cladding, and catalyzing the hydrothermal product by hydrogen and calcining to obtain the three-dimensional composite material formedby filling the graphene layers with the carbon-encapsulated tin granules. The advantages of the three-dimensional composite material and the preparation method are that: the preparation process is safe and harmless, and simple in operation; the prepared three-dimensional composite material formed by filling the graphene layers with the carbon-encapsulated tin granules is high in reversible capacity, high in cycling stability, and excellent in rate capacity when the three-dimensional composite material is used as the cathode material of lithium ion batteries.

Description

technical field [0001] The invention relates to a composite material of carbon-coated tin particles filled between three-dimensional graphene layers and a preparation method thereof, belonging to the field of lithium-ion secondary battery electrode materials. Background technique [0002] Traditional coal, oil and other fuels have always been the main energy sources for human beings. However, with their massive consumption, they not only caused an energy crisis, but also seriously polluted the air. The ever-increasing smog reminds people that it is imminent to find new clean and renewable energy sources. . In recent years, as new energy sources, water energy, wind energy, solar energy, batteries, capacitors and other industries have developed rapidly. Among them, lithium-ion secondary batteries have received widespread attention due to their advantages such as high energy density, wide operating range, high discharge voltage, no environmental pollution, and no memory effect...

AI Technical Summary

Problems solved by technology

There are two main approaches to the traditional graphene sandwich structure: one is to use the stacking between the sheets when reducing graphene oxide, so that the active metal particles are sandwiched in the graphene sheets, so as to obtain graphene-active metal-graphite The sandwich structure of ene; the second is to make the active metal material supported on the graphene sheet, and then carbon coating, so that the outermost layer is covered with a layer of carbon, so as to obtain the graphene-active metal-amorphous carbon structure , and the sandwich structure of three-dimensional graphene is rarely reported due to the difficulty of preparation.

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