Lithium-sulfur battery positive pole framework material and preparation method thereof, lithium-sulfur battery positive pole material and lithium-sulfur battery

Abstract

The invention provides a lithium-sulfur battery positive pole framework material and a preparation method thereof, a lithium-sulfur battery positive pole material and a lithium-sulfur battery, and belongs to the field of lithium-sulfur batteries. The lithium-sulfur battery positive pole framework material provided by the invention is a hollow porous carbon material doped with Co and N, the hollowporous carbon material is of a flower-like structure, and the interior of the flower-like structure is a hollow structure, petals of the flower-like structure are carbon nanosheets, Co and N active sits are attached to the pedals, and the pedals are of porous structures. According to the lithium-sulfur battery positive pole framework material provided by the invention, the volume expansion of active substances during charging and discharging processes can be effectively relieved; via the dual active sires of Co-N, the polysulfide is effectively adsorbed, the conversion of the polysulfide to the solid Li2S2 / Li2S is accelerated, the shuttle effect of the polysulfide is suppressed from the source, and thus the specific capacity, rate performance and stability of the positive pole material areimproved.

Description

technical field [0001] The invention relates to the field of lithium-sulfur batteries, in particular to a lithium-sulfur battery cathode framework material and a preparation method thereof, a lithium-sulfur battery cathode material and a lithium-sulfur battery. Background technique [0002] Lithium-sulfur batteries are considered to be one of the most promising high-energy-density energy storage devices for the next generation because of their theoretical specific capacity and theoretical energy density as high as 1675mAh / g and 2600 Wh / kg, as well as their environmental friendliness and low cost. one. However, the commercial application of lithium-sulfur batteries still faces many severe challenges, such as the volume effect during the sulfur cycle, the shuttling effect caused by polysulfide dissolution, and the slow kinetics of polysulfide reactions. During the discharge process of lithium-sulfur batteries with high sulfur loading and long cycle, the slow polysulfide kinet...

AI Technical Summary

Problems solved by technology

However, the commercial application of lithium-sulfur batteries still faces many severe challenges, such as the volume effect during the sulfur cycle, the shuttling effect caused by polysulfide dissolution, and the slow kinetics of polysulfide reactions, etc.

During the discharge process of lithium-sulfur batteries with high sulfur loading and long cycle, the slow polysulfide kinetics will make the insoluble Li 2 S 2 and Li 2 S is obviously deposited on the surface of the electrode, resulting in the continuous loss of the active material sulfur, and the serious attenuation of the battery capacity, so that the battery gradually fails.

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