Preparation method of sodium-ion battery modified titanium dioxide-graphene anode material

Abstract

The invention discloses a preparation method of a sodium-ion battery modified titanium dioxide-graphene anode material. The preparation method comprises following steps: 1, tetrabutyl titanate is added into absolute ethyl alcohol, a graphene aqueous solution is added, and uniform stirring is carried out at normal temperature; 2, an obtained uniformly mixed solution from step 1 is subjected to centrifugal operation so as to obtain a precipitate, and the precipitate is subjected to freeze drying so as to obtain titanium dioxide / graphene composite nanometer sheets; 3, the titanium dioxide / graphene composite nanometer sheets are subjected to high temperature phosphatization processing in a phosphorus-containing atmosphere so as to obtain phosphor doped titanium dioxide / graphene composite nanometer sheets. According to the preparation method, graphene nanometer sheets are taken as a template so as to obtain the titanium dioxide / graphene composite nanometer sheets, the electric conductivityof the composite electrode material is improved; and phosphor doping is capable of improving titanium dioxide surface sodion transmission capability, and improving the sodium storage performance of the titanium dioxide / graphene composite electrodes.

Description

technical field [0001] The invention belongs to the field of sodium ion batteries, and relates to a preparation method of a sodium ion battery modified titanium dioxide-graphene negative electrode material. Background technique [0002] The rapid economic development has made the human society's demand for energy higher and higher, and the energy problem is gradually becoming a major challenge affecting the sustainable development of my country's economy and society. In order to change the unreasonable energy structure, clean renewable energy has been extensively developed to replace traditional fossil fuels. However, the large-scale energy storage of renewable resources and the construction of smart grid are still urgent problems to be solved. At present, lithium-ion batteries have been widely used in portable devices due to their high operating voltage and high energy density. In recent years, their applications have also been extended to electric vehicles. However, the s...

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Problems solved by technology

However, due to the poor electronic and ionic conductivity of titanium dioxide, the intercalation and extraction of sodium ions in the electrode material is difficult, the actual obtained titanium dioxide negative electrode material has a low specific capacity, and the energy storage performance needs to be improved urgently.

At present, there are mainly three ways to improve the sodium storage performance of titanium dioxide negative electrode: (1) Synthesizing titanium dioxide electrode materials with nano-morphology, such as nanosheets, nanospheres, nanorods, etc., although this method can improve titanium dioxide to a certain extent It has excellent sodium storage performance, but it is prone to side reactions, leading to problems such as low Coulombic efficiency; (2) Combining titanium dioxide with carbon materials with excellent conductivity, this method can have a three-dimensional conductive network structure and a stable solid electrolyte interface film, The first-time Coulombic efficiency and rate performance have been improved, but it is still necessary to find a synthesis method suitable for large-scale production; (3) Doping with impurity atoms, which can effectively improve the ion and electronic conductivity of electrode materials by increasing the structural defects of titanium dioxide However, the first Coulombic efficiency of electrode materials still needs to be improved

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