Lithium-sulfur battery positive electrode material and preparation method thereof

Abstract

The invention discloses a lithium-sulfur battery positive electrode material and a preparation method thereof. The method comprises the steps of providing a metal-organic framework material; dissolving the metal-organic framework material, a sulfur source and a polymer in a solvent, stirring for 1-12 hours, and controlling the temperature at 0-30 DEG C to obtain a spinning solution; carrying out electrostatic spinning on the spinning solution to obtain a polymer / metal organic framework film; sequentially carrying out pre-oxidation, carbonization and acid solution treatment on the film to obtain sulfur and nitrogen co-doped porous carbon nanofibers; and mixing the porous carbon nanofibers with sulfur powder, and heating and preserving heat for 1-12 hours in an inert atmosphere to obtain thelithium-sulfur battery positive electrode material. The sulfur and nitrogen co-doped porous carbon nanofiber prepared by adopting the preparation method has a large specific surface area and a rich pore structure. The lithium-sulfur battery positive electrode material serves as the positive electrode of a lithium-sulfur battery after being loaded with sulfur, which not only improves the conductivity of the sulfur electrode and relieves the influence caused by volume expansion of sulfur, but also can effectively inhibit the shuttle effect of sulfur.

Description

technical field

[0001] The invention relates to the field of lithium-sulfur battery cathode materials, in particular to a lithium-sulfur battery cathode material and a preparation method thereof. Background technique

[0002] Environmental pollution and fossil energy depletion are becoming more and more serious, and lithium-ion batteries with long cycle life and high energy density are considered to be an effective way to solve these problems. However, the theoretical energy density of Li-ion batteries based on "intercalation" electrochemistry is only 387 W h kg -1 . In this case, the lithium-sulfur battery (Li-S) based on the "conversion" electrochemical mechanism due to its high specific capacity (1675mA h g -1 ) and energy density (2600W h·kg -1 ) has received a lot of attention. In addition, sulfur also has the advantages of economy, environmental protection and abundant resources. However, the practical application of Li-S batteries is constrained: (i) the insulati...

Images