Bicontinuous nanoporous carbon material co-doped with nitrogen and oxygen, its preparation method and application

Abstract

The invention discloses a bicontinuous nanoporous carbon material co-doped with nitrogen and oxygen, its preparation method and application. The carbon dioxide in the polyacrylonitrile membrane is saturated by supercritical carbon dioxide foaming, and the polyacrylonitrile membrane containing saturated carbon dioxide is processed. The polyacrylonitrile nanoporous foam is obtained by heat treatment in a water bath, and the polyacrylonitrile nanoporous foam is sequentially subjected to pre-oxidation treatment and carbonization treatment to obtain a nitrogen-oxygen co-doped bicontinuous nanoporous carbon material. The nanoporous carbon material has a continuous nano-mesoporous and macroporous scaffold structure with a large specific surface area, and the scaffold structure has a large number of micropores; the BET specific surface area is 200-400m 2 g ‑1 ; Containing 70-90at% of carbon element, 5-20at% of nitrogen element and 5-10at% of oxygen element. The nitrogen-oxygen co-doped bicontinuous nanoporous carbon material prepared by the invention can take into account excellent reversible specific capacity, rate performance and cycle stability when used as a negative electrode of a potassium ion battery.

Description

technical field [0001] The invention relates to the technical field of preparation of nanoporous carbon materials, in particular to bicontinuous nanoporous carbon materials co-doped with nitrogen and oxygen, as well as its preparation method and application. Background technique [0002] The information disclosed in this background section is only intended to increase the understanding of the general background of the present invention, and is not necessarily taken as an acknowledgment or any form of suggestion that the information constitutes the prior art already known to those skilled in the art. [0003] Lithium-ion batteries have been widely used in communication equipment, electronic equipment and electric vehicles due to their stable and high energy storage capacity. However, the uneven distribution and insufficient reserves of lithium resources on the earth limit the large-scale application of lithium-ion batteries. In recent years, due to the abundance of potassium...

AI Technical Summary

Problems solved by technology

However, the inventors found that when designing a porous structure, the existing methods usually require the use of templates. In order to ensure the complete removal of the templates, the materials need to be washed repeatedly with strong acid or other corrosive chemical reagents. The post-treatment steps restrict its practical application in the preparation of porous carbon anode materials. At the same time, the complicated post-treatment will also affect the formed porous structure, thereby affecting the electrochemical performance of nitrogen-oxygen co-doped porous carbon materials.

Therefore, it is still a great challenge to develop a template-free and scalable method to prepare nitrogen-oxygen co-doped nanoporous carbon materials.

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