Transition metal cobalt single atom/cluster embedded nitrogen-doped carbon skeleton material, and preparation method and application thereof

Abstract

The invention discloses a transition metal cobalt single atom / cluster embedded nitrogen-doped carbon skeleton material, and a preparation method and application thereof. The preparation method comprises the following steps: adding a cobalt source, a nitrogen-containing carbon source and silicon dioxide into a solvent, and carrying out ultrasonic stirring; carbonizing the obtained mixture in an inert atmosphere; carrying out pickling and etching on the obtained product in hydrochloric acid and hydrofluoric acid, and then washing and drying to obtain the transition metal cobalt single atom / cluster embedded nitrogen-doped carbon skeleton material. The method is simple in step and high in repeatability, and for the transition metal cobalt single atom / cluster embedded nitrogen-doped carbon skeleton, a mixed structure is endowed with enhanced electron conduction, and a large amount of uniformly dispersed N-C and Co-Nx active sites are introduced, thereby facilitating absorption of lithium ions and promotion of the interface reaction of the electrode material and the electrolyte. When being used as a lithium ion battery negative electrode material, the metal cobalt single atom / cluster embedded carbon hybrid material shows ultrahigh electrochemical activity and has very high potential application value.

Description

technical field [0001] The invention relates to the field of negative electrode materials for lithium-ion batteries, in particular to a transition metal cobalt single atom / cluster intercalated with nitrogen-doped carbon skeleton material, a preparation method thereof, and an application in a lithium-ion battery system. Background technique [0002] Lithium-ion batteries (LIBs) have the characteristics of high energy density, long life and environmental protection, and are currently one of the most attractive energy storage devices, and are widely used in the market of portable electronic products such as mobile phones, notebook computers and digital cameras . At the same time, they are also considered as the preferred power source for electric vehicles and stationary energy storage systems. However, the current state-of-the-art LIBs are still unable to meet the growing demands in the fields of high-power electric vehicles and large-scale energy storage. Because most commer...

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Problems solved by technology

[0003] The purpose of the present invention is to address the above-mentioned defects of existing materials, in order to solve the problems of low capacity, poor rate performance and short cycle life of lithium-ion battery electrode materials, a transition metal cobalt single atom / cluster embedded nitrogen is designed and synthesized A method for preparing a doped carbon skeleton material. The preparation method uses a high-temperature carbonization-hard template etching method to construct transition metal cobalt single atoms / clusters embedded in nitrogen-doped carbon skeleton materials, and utilize the high conductivity of metal cobalt to greatly It enhances the electronic conductance of the hybrid material, which is conducive to the rapid conduction of electrons during the electrochemical reaction, and at the same time introduces a large amount of N-C and Co-N x The active sites can be evenly penetrated throughout the material, thereby enhancing the adsorption energy of lithium, synergistically promoting the interface reaction between the electrode material and the electrolyte, and greatly improving the electrochemical performance of the material

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