Niobium pentoxide/carbon double-quantum-dot nanometer composite material, method for preparing same and application of niobium pentoxide/carbon double-quantum-dot nanometer composite material

Abstract

The invention discloses a niobium pentoxide / carbon double-quantum-dot nanometer composite material, a method for preparing the same and application of the niobium pentoxide / carbon double-quantum-dot nanometer composite material. The niobium pentoxide / carbon double-quantum-dot nanometer composite material comprises niobium pentoxide and carbon double quantum dot. The niobium pentoxide quantum dot and the carbon double quantum dot are closely bonded with each other; the mass fraction of the carbon quantum dot in the niobium pentoxide / carbon double-quantum-dot nanometer composite material is 20-40%. The niobium pentoxide / carbon double-quantum-dot nanometer composite material, the method and the application have the advantages that gaps are reserved between particles of the niobium pentoxide / carbon double quantum dots, and accordingly the niobium pentoxide / carbon double-quantum-dot nanometer composite material has large specific surface areas; the niobium pentoxide / carbon double-quantum-dot nanometer composite material with the structure is favorable for sufficient contact of electrolyte solution and active substances and further can effectively adapt to volume expansion of materials in charge and discharge procedures, and accordingly the electrochemical performance of the niobium pentoxide / carbon double-quantum-dot nanometer composite material can be greatly improved when the niobium pentoxide / carbon double-quantum-dot nanometer composite material is used as a negative electrode material for lithium ion batteries; precursors of niobium and carbon quantum dots are synthesized by the aid of hydrothermal processes at first and then are calcined in argon atmosphere to obtain the niobium pentoxide / carbon double-quantum-dot nanometer composite material; the method is convenientand easy to operate, reaction conditions can be controlled, and scale-up experiments can be facilitated.

Description

technical field

[0001] The invention belongs to the technical field of lithium ion battery negative electrode material preparation, and in particular relates to a niobium pentoxide / carbon double quantum dot nanocomposite material, a preparation method thereof and an application in lithium ion batteries. Background technique

[0002] Lithium-ion batteries have been used in more and more fields, such as electric vehicles, notebook computers, mobile phones, etc., due to their advantages such as high energy density, long cycle life, environmental friendliness and no pollution. In order to meet the better application of lithium-ion batteries, its anode materials have been extensively studied. Among them, transition metal oxides have received great attention because of their high theoretical specific capacity, abundant reserves, and mature preparation processes. In the study of transition metal oxide anode materials, lithium titanate (Li 4 Ti 5 o 12 ) and niobium oxide (Nb 2 ...

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