Lithium-sulfur battery separator and lithium-sulfur battery

Abstract

The invention relates to a lithium-sulfur battery separator, comprising a separator substrate and a functional layer, the functional layer covers the surface of the separator substrate, and the functional layer includes at least two layers of carbon nanotube layers and at least two layers of graphite oxide ene composite layer, the at least two layers of carbon nanotube layers and at least two layers of graphene oxide composite layers are alternately stacked on each other, and the graphene oxide composite layer includes a plurality of graphene oxide sheets and a plurality of manganese dioxide nanoparticles, so The plurality of graphene oxide sheets overlap each other, and the plurality of manganese dioxide nanoparticles are uniformly adsorbed on the graphene oxide sheets. The present invention further provides a lithium-sulfur battery comprising the above lithium-sulfur battery separator.

Description

technical field [0001] The invention relates to a lithium-sulfur battery diaphragm and a lithium-sulfur battery, in particular to a lithium-sulfur battery diaphragm and a lithium-sulfur battery based on a carbon nanotube film. Background technique [0002] Lithium-sulfur batteries use sulfur as the positive electrode and metallic lithium as the negative electrode. During discharge, the negative electrode reaction is that lithium loses electrons and becomes lithium ions, and the positive electrode reaction is that sulfur reacts with lithium ions and electrons to form sulfide. The reaction equation is: S 8 +16Li + +16e -1 =8Li 2 S. Due to the occurrence of multiple electron transfer reactions, it has a high theoretical specific capacity, with a specific capacity as high as 1672 mAh g -1 . In addition, because sulfur has the characteristics of less environmental pollution, non-toxicity, low cost, and wide source of raw materials, lithium-sulfur batteries have received mor...

AI Technical Summary

Problems solved by technology

Lithium-sulfur battery separators are usually non-polar films such as polypropylene / polyethylene (PP / PE). However, the polysulfides produced during the discharge process of lithium-sulfur batteries have high polar characteristics and are easily soluble in the electrolyte. Therefore, it is difficult for lithium-sulfur battery separators to inhibit the diffusion of polysulfides, and then make polysulfides shuttle between the positive electrode and the negative electrode, resulting in irreversible damage to the sulfur-containing structure of the positive electrode.

The shortcomings of the above-mentioned separators lead to a series of problems such as poor cycle stability, low actual specific capacity, and poor rate characteristics of lithium-sulfur batteries.

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