Preparation method and application of carbon-coated grapheme-based metal oxide composite

Abstract

The invention discloses a preparation method and application of a carbon-coated grapheme-based metal oxide composite in a two-dimensional core-shell structure. The carbon-coated grapheme-based metal oxide composite in the two-dimensional core-shell structure is prepared by taking the two-dimensional grapheme in a single-layer carbon atom structure as a carrier and the phenolic resin or polysaccharide as the carbon source precursor. The metal oxide nanoparticles obtained by the method are uniformly loaded on a graphene sheet and well coated in the carbon-coated layer. The preparation method has the advantages of simple process, mild condition and low cost. The Electrochemical tests prove that the carbon-coated grapheme-based metal oxide composite in the two-dimensional core-shell structure has excellent cycle stability and rate properties. The experiments prove that: under the charge and discharge current of 200mAhg<-1>, the tin dioxide material has the discharge capacity of 200mAhg<-1>, and the ferroferric oxide material has the discharge capacity of 930mAhg<-1>. Therefore, better experimental data and theoretical support are provided for the research and the application of the metal oxide in the field of electrochemistry.

Description

technical field [0001] The invention relates to a method and application of a carbon-coated graphene-based metal oxide composite material, in particular to a method and application of a carbon-coated graphene-based metal oxide composite material with a two-dimensional shell-core structure. It belongs to the field of material science and electrochemical technology. Background technique [0002] With the increasingly prominent energy and environmental issues, the new energy industry has received more and more attention. The hybrid electric vehicle and electric vehicle industries are developing rapidly, and lithium-ion batteries are widely used as an important energy storage device. Lithium-ion batteries have some excellent properties such as high energy density and good cycle performance, and are considered to be one of the most effective energy storage methods at present. Therefore, further improving their energy density and cycle performance is also a difficult and hot topi...

AI Technical Summary

Problems solved by technology

At present, graphite is the main anode material for commercial lithium-ion batteries. Graphite has low cost and wide sources, and is suitable for commercialization; however, its capacity is relatively low, and its theoretical capacity is only 372mAhg. -1 , which is limited when applied in fields requiring high energy output

[0004] Metal oxides such as Fe 3 o 4 , SnO 2 As a negative electrode material for lithium-ion batteries, it has a high specific capacity, and its specific capacity is as high as 700-1000mAh g -1 ; but most metal oxides, especially SnO 2 As an electrode material, the volume change is as high as 200-300% during the charging and discharging process, which will cause the pulverization of the electrode, resulting in the disconnection of the active material and the current collector.

Therefore, most metal oxides have the problem of rapid capacity decay when used as electrodes of lithium-ion batteries, which also limits the development and practical application of metal oxides as anode materials for lithium-ion batteries.

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