Preparation method of nitrogen-doped three-dimensional porous carbon loaded with nano cobalt and application thereof in lithium sulfur batteries

Abstract

The invention discloses a preparation method of nitrogen-doped three-dimensional porous carbon loaded with nano cobalt and an application thereof in lithium sulfur batteries. The method includes the following steps: preparing precursor solution containing an inorganic nanosphere template; preparing a precursor by using cobalt salt and 2-methylimidazole as a cobalt source, a carbon source and a nitrogen source and using inorganic nanospheres as a template, and carbonizing and reducing the precursor at high temperature; and finally, removing part of the template and part of metal cobalt to obtain nitrogen-doped three-dimensional porous carbon loaded with nano cobalt. According to the preparation method provided by the invention, the precursor is prepared through a stirring evaporation solvent method by using cobalt salt as a cobalt source, 2-methylimidazole as a carbon source and a nitrogen source and inorganic nanospheres as a template, which makes the yield of the precursor close to 100%, can improve the yield of the final product, namely, the nitrogen-doped three-dimensional porous carbon loaded with nano cobalt, and is beneficial to large-scale production and preparation. The three-dimensional porous carbon prepared by the preparation method can be used in lithium sulfur batteries to improve the sulfur loading capacity and electrochemical performance of lithium sulfur batteries.

Description

technical field

[0001] The invention relates to the technical field of nano-carbon materials and their preparation, in particular to a method for preparing nano-cobalt-loaded nitrogen-doped three-dimensional porous carbon and its application in lithium-sulfur batteries. Background technique

[0002] Lithium-sulfur batteries have the advantages of high theoretical specific capacity (1672mAh / g) and high energy density (2600Wh / kg), as well as abundant sulfur resources, low price, and environmental friendliness, and are regarded as the most promising next-generation high-energy batteries. Density secondary power. However, the following problems in lithium-sulfur batteries restrict its performance: (1) The conductivity of the sulfur cathode is poor (only 5×10 -30 S / cm), seriously reducing the utilization rate of sulfur and the rate performance of the battery; (2) the long-chain lithium polysulfide (Li 2 S x , x=3~8) dissolved in the ether electrolyte, forming a "shuttle" effec...

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