Nitrogen-oxygen co-doped bicontinuous nano-porous carbon material as well as preparation method and application thereof

Abstract

The invention discloses a nitrogen-oxygen co-doped bicontinuous nano-porous carbon material as well as a preparation method and application thereof. According to the invention, carbon dioxide in a polyacrylonitrile membrane is saturated through supercritical carbon dioxide foaming, and the polyacrylonitrile membrane containing the saturated carbon dioxide is subjected to water-bath heat treatmentto obtain polyacrylonitrile nano-porous foam; and the polyacrylonitrile nano-pore foam is sequentially subjected to pre-oxidation treatment and carbonization treatment to obtain the nitrogen-oxygen co-doped bicontinuous nano-porous carbon material. The nano-porous carbon material has a continuous nano-mesoporous and macroporous scaffold structure with a large specific surface area, and a large number of micropores are formed in the scaffold structure; the BET specific surface area of the material is 200 to 400 m<2> / g; and the carbon element accounts for 70-90 at%, the nitrogen element accountsfor 5-20 at%, and the oxygen element accounts for 5-10 at%. When the nitrogen-oxygen co-doped bicontinuous nano-porous carbon material prepared by the method is used as a negative electrode of a potassium ion battery, excellent reversible specific capacity, rate capability and cycling stability can be obtained.

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...

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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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