Nitrogen-doped graphene and nitrogen-doped nano tin dioxide composite material and preparation method and application thereof

Abstract

The invention provides a nitrogen-doped graphene and nitrogen-doped nano tin dioxide composite material and a preparation method and application thereof, and the preparation method comprises the following steps: respectively preparing graphene, a tin salt and a nitrogen-containing compound serving as raw materials into solutions; and carrying out mixing, heat treatment, heat preservation and drying to obtain the composite material. In the composite material, the mass percentage ratio of the nitrogen-doped graphene to the nitrogen-doped nano tin dioxide is 5%: 95%-30%: 70%. The crystal grain size of the nitrogen-doped nano tin dioxide is 1-5 nm, the Nitrogen-doped nano tin dioxide is uniformly loaded on the nitrogen-doped graphene. The total nitrogen doping amount of the nitrogen-doped graphene and nitrogen-doped nano tin dioxide composite material is 0.5%-1% of atomic ratio, and the specific surface area is 300-450m<2> / g. By use of the composite material disclosed by the invention, theelectron and lithium ion transmission speed can be effectively improved; the composite material can be used as a negative electrode material of a lithium ion battery; and the method has the advantages of few process steps, easiness in control, high repeatability and high product yield, thereby being beneficial to large-scale popularization.

Description

[0001] 【Technical field】 [0002] The invention relates to the field of material chemistry, in particular to a composite material of nitrogen-doped graphene and nitrogen-doped nano-tin dioxide, and a preparation method and application thereof. [0003] 【Background technique】 [0004] The development of electric vehicles is one of the important strategies for my country to achieve energy conservation and emission reduction. Lithium-ion batteries for electric vehicles need to further improve the energy density and power density of batteries. Carbon negative electrode is currently a commonly used negative electrode material for lithium-ion batteries, and its theoretical capacity is low, only 374mAhg -1 , can not meet the energy density and power density requirements of lithium-ion batteries for electric vehicles, so the development of new high-capacity and high-performance lithium-ion battery anode materials is called a research hotspot in the field of lithium-ion batteries. Tin ...

AI Technical Summary

Problems solved by technology

Carbon negative electrode is currently a commonly used negative electrode material for lithium-ion batteries, and its theoretical capacity is low, only 374mAhg -1 , cannot meet the energy density and power density requirements of lithium-ion batteries for electric vehicles, so the development of new high-capacity and high-performance lithium-ion battery anode materials is called a research hotspot in the field of lithium-ion batteries

Tin dioxide material is an extremely important semiconductor oxide material, as the negative electrode material of lithium-ion batteries, it has a capacity of up to 950mAhg -1 The theoretical capacity has a good application prospect in lithium-ion batteries, but it will undergo a large volume change during the lithium-ion deintercalation process, which will easily cause the electrode material to fall off from the current collector matrix, thereby rapidly deteriorating the battery performance. In addition, the electronic conductivity of tin dioxide needs to be further improved to optimize the transport path of carriers

However, due to the lack of effective synthesis methods at present, the preparation method and related composite materials for simultaneously realizing the nitrogen doping of nano-tin dioxide and graphene have not been reported.