Nano bismuth/nitrogen-doped carbon foam nanosheet two-dimensional composite material as well as preparation method and application thereof

Abstract

The invention belongs to the field of preparation engineering of composite nano materials, and particularly relates to a nano bismuth / nitrogen-doped carbon foam nanosheet two-dimensional composite material as well as a preparation method and application thereof. According to the invention, a two-dimensional bismuth-based metal organic framework compound precursor is prepared through a solvothermalreaction technology, and then the nano bismuth / nitrogen-doped carbon foam nanosheet composite material is controllably synthesized through a carbothermal reduction technology. The method comprises the steps of adding a bismuth source and trimesic acid into ethylene glycol, stirring, carrying out hydro-thermal treatment to form a mixed solution, separating to obtain a precursor, drying, adding melamine, and carrying out carbon thermal reduction to generate the nitrogen-doped carbon nano-foam nanosheet composite material containing nano bismuth particles. The Nano bismuth particles in the two-dimensional nanosheet composite material are limited in a nitrogen-doped carbon nano-foam cavity to form an egg yolk-shell microstructure. The bismuth nano-particles of the prepared nano composite material are good in size controllability, and the nano composite material shows excellent electrochemical performance when being used as a negative electrode material of a potassium ion battery.

Description

technical field [0001] The invention belongs to the technical field of preparation of nano-composite materials, and in particular relates to a nano-bismuth / nitrogen-doped carbon foam nanosheet two-dimensional composite material and a preparation method and application thereof. Background technique [0002] Nanobismuth / nitrogen-doped carbon foam nanosheet two-dimensional composite material is a new type of metal bismuth and carbon composite material. Its advantage is that the coated carbon layer can buffer the volume change of bismuth metal during charge and discharge reactions. . Most of the existing bismuth / carbon composite materials use graphene as the carbon source, and then compound with metal bismuth through ball milling, etc., and the bismuth / carbon composite materials prepared in this way are prone to solid state during the electrochemical reaction with potassium ions. The rupture of the electrolyte interface (SEI) film reduces the Coulombic efficiency, thereby short...

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Problems solved by technology

Most of the existing bismuth / carbon composite materials use graphene as the carbon source, and then compound with metal bismuth through ball milling, etc., and the bismuth / carbon composite materials prepared in this way are prone to solid state during the electrochemical reaction with potassium ions. Cracking of the electrolyte interface (SEI) film reduces the Coulombic efficiency and thus shortens the cycle life of potassium-ion batteries

[0003] The literature "Qing Zhang, Jianfeng Mao, Wei Kong Pang, Tian Zheng, VitorSecadas, Yuanzhen Chen, Yajie Liu, and Zaiping Guo; Adv. Energy Mater. 2018, 1703288" reported that a mixed solution of graphene oxide was prepared using the commonly used Hummers method. Then generate Bi / rGO composite electrode material by hydrothermal synthesis method. This kind of synthesis method has high risk, and the sample graphene coating is uneven, and it has high requirements for large-scale production, so it is difficult to realize industrial production; therefore, the development of a This kind of compound electrode material is suitable for large-scale industrial production, has low risk factor, controllable particle size, and good structural stability, and has significant economic and social benefits.

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