Method for preparing reduced graphene oxide load ReS2 for cathode material of lithium sulfur battery

Abstract

The invention relates to a method for preparing reduced graphene oxide load ReS2 for a cathode material of a lithium sulfur battery. The method comprises steps that 1), graphene oxide dispersion is prepared through utilizing single-layer graphene oxide powder; preparation of reduced graphene oxide-loaded ReS2 nanosheet, according to the mass ratio of ammonium perrhenate and thiourea and the single-layer graphene oxide powder (0.3-0.7) ): (0.8-1.2): 1, the ammonium perrhenate and thiourea are weighed and added to the graphene oxide dispersion to obtain uniform mixture solution, the mixture solution is transferred to a reaction vessel and then heated to 150-240 DEG C for 10-24 hours, and a reaction product is obtained; the reduced graphene oxide load ReS 2 nanosheet is calcined to improve the crystallinity of the material, and the final product rGO / ReS2 is obtained.

Description

technical field [0001] The invention belongs to the technical field of electrode materials for lithium-sulfur batteries, and in particular relates to a reduced graphene oxide-loaded ReS used for lithium-sulfur battery positive electrodes, which can effectively inhibit the dissolution of lithium polysulfide, accelerate reaction kinetics, and inhibit sulfur volume expansion. 2 Preparation method of composite sulfur cathode. Background technique [0002] With the aggravation of energy crisis and environmental pollution, it is imminent to develop clean energy such as solar energy and wind energy and effectively collect and utilize them. However, the specific capacity of the current commercial lithium-ion battery cathode materials is limited by its intercalation and extraction mechanism, and it is difficult to meet the demand for high energy density. Therefore, the development of new alternative cathode materials is the current research focus of secondary batteries. The sulfur c...

AI Technical Summary

Problems solved by technology

However, the sulfur cathode has the following problems: first, during the discharge process, sulfur will be reduced to lithium sulfide, and the process will undergo multi-step reduction reactions, undergoing solid-liquid-solid transformation, and generate a variety of long-chain lithium polysulfides (Li 2 S x , 4≤x≤8) and then reduced to Li 2 S 2 and Li 2 S, in which the long-chain lithium polysulfide is easily dissolved in the ether electrolyte, resulting in the loss of active materials, resulting in capacity decay and poor cycle stability

Among them, carbon materials mainly include porous carbon, hollow carbon spheres, graphene, carbon nanotubes, carbon nanofibers, etc., which mainly bind lithium polysulfide through physical adsorption, and the excellent conductivity of carbon materials also makes up for the sulfur The disadvantage of poor conductivity, but the binding force between non-polar carbon and polar lithium polysulfide is van der Waals force, which is a weak combination, so it cannot effectively inhibit the dissolution and diffusion of lithium polysulfide

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