Method for preparing graphene wrapped 3D flowerlike nickel sulfide/foamed nickel material

Abstract

The invention discloses a method for preparing a graphene wrapped 3D flowerlike nickel sulfide / foamed nickel material. The method comprises the following steps: preparing a nickel sulfide / foamed nickel composite material by using a hydrothermal method, and performing vulcanization treatment on the surface of the foamed nickel by taking thioacetamide as a sulfur source so as to grow flaky nickel sulfide uniformly on the surface of the foamed nickel; wrapping the surface of the nickel sulfide / foamed nickel with a layer of graphene oxide through physical adsorption; performing thermal expansion and reduction on the adsorbed graphene oxide by using a rapid thermal expansion method, thereby obtaining the graphene wrapped composite material. The method is wide in nickel sulfide material source and simple in preparation process, the lithium extraction and insertion efficiency can be improved, and the electrochemical properties of the material can be improved; the conductivity and the structural stability of the material are improved, and the internal resistance of the material can be reduced; the electric conductivity of the material is improved, and effective pores can be provided for extraction and insertion of lithium ions due to C vacancy generated in the reduction process of the graphene.

Description

technical field [0001] The invention belongs to the technical field of lithium-ion batteries, and in particular relates to a preparation method of a graphene-coated 3D flower-shaped nickel sulfide / foam nickel material. Background technique [0002] At present, the methods for preparing nickel sulfide materials are mainly divided into the following types, one is to directly synthesize nickel sulfide powder materials, and the other is to grow nickel sulfide materials on the surface of nickel foam. The synthesis of nickel sulfide powder materials mainly uses metal nickel powder or nickel salt as raw material, and selects a certain sulfur source for sulfide preparation. Jia-Jia Li et al. selected metallic nickel powder as the nickel source and sulfur as the sulfur source. The two were fully ground and mixed by ball milling to obtain a nickel sulfide precursor, and then the excess sulfur was removed by high-temperature calcination. Jun Song Chen et al. choose NiSO 4 ·6H 2 O wa...

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Problems solved by technology

[0004] The purpose of the present invention is to provide a preparation method of graphene-coated 3D flower-shaped nickel sulfide / nickel foam material, aiming to solve the problem that lithium sulfide is easily dissolved into the electrolyte and cause the loss of sulfur element, so that the lithium storage performance of the material is greatly improved. decrease, leading to the problem of rapid decay of the cycle performance and rate performance of the battery

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