Method of preparing stannic oxide/graphene composite lithium ion battery anode material under the assistance of chitosan oligosaccharide self-assembly

Abstract

The invention discloses a method of preparing a stannic oxide / graphene composite lithium ion battery anode material under the assistance of chitosan oligosaccharide self-assembly. The method includes: 1) adding sodium stannate and chitosan oligosaccharide into water to form a nanometer stannic oxide self-assembly precursor modified by the chitosan oligosaccharide; 2) adding graphene oxide into the self-assembly precursor to obtain a solution mixture, and mixing and reacting at 20-60 DEG C for 6-20 h to obtain the nanometer stannic oxide / graphene oxide composite material modified by the chitosan oligosaccharide; and 3) washing to remove the chitosan oligosaccharide after solid-liquid separation, and drying to prepare the stannic oxide / graphene composite lithium ion battery anode material. The method can be performed at room temperature under normal pressure, and is free of use of organic solvent, convenient in operation, easily available in raw materials, free of pollution and prone to popularization and application. The stannic oxide / graphene composite lithium ion battery anode material prepared by the method has good electrochemical properties, can be used for preparing lithium ion battery anodes, and has wide market and application prospect.

Description

technical field [0001] The invention belongs to the technical field of materials and chemical power sources, and in particular relates to a method for preparing tin dioxide / graphene composite lithium-ion battery negative electrode materials aided by chitosan oligosaccharide self-assembly. Background technique [0002] Lithium-ion batteries have the advantages of high operating voltage, high specific energy, wide operating temperature range, and stable discharge. The current commercial lithium-ion battery negative electrode active material is mainly graphite, but its theoretical specific capacity is only 372mAh / g, which is difficult to meet the energy density and power density requirements of the power field such as electric vehicles. Tin dioxide has a higher specific capacity (790mAh / g) than graphite, is cheap and non-toxic, and is considered to be a promising electrode material for lithium-ion batteries. However, the volume of tin dioxide will change drastically during cha...

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Problems solved by technology

For example, the Chinese invention patent application whose application number is CN201310025748.2 discloses a method of a tin dioxide / graphene composite lithium ion battery negative electrode material, which makes stannous chloride and graphene oxide react with choline chloride and ethyl The reaction is carried out in a non-aqueous solution composed of diols, which requires a large amount of organic solvents, which is not conducive to environmental protection and increases costs

For example, the Chinese invention patent application with the application number CN201110159043.0 discloses a graphene macroscopic body / tin oxide composite lithium-ion battery negative electrode material and its technology. The three-dimensional porous graphene is soaked in the hydrochloric acid solution of tin salt, and then the Or under argon protection, heat treatment at a temperature of 200°C to 600°C for 1 to 10 hours, which not only pollutes the environment but also consumes a lot of energy

For example, the Chinese invention patent application with the application number CN201110271670.3 discloses a method for a flower-shaped tin dioxide and graphene composite material, which requires a hydrothermal reaction at a temperature of 160°C to 250°C for 2 to 36 hours, and the reaction conditions require Harsh, prolonged high temperatures lead to higher production costs

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