Self-supporting lithium-sulfur battery cathode material with high sulfur load and preparation method of self-supporting lithium-sulfur battery cathode material

Abstract

The invention provides a self-supporting lithium-sulfur battery cathode material with high sulfur load and a preparation method of the self-supporting lithium-sulfur battery cathode material. The cathode material comprises carbon-coated sulfur nanosheets, carbon nanotubes as a conductive agent and bacterial cellulose as a binder in a mass ratio of (8-9) :( 0.5-1): (0.5-1), wherein the carbon-coated sulfur nanosheets are also prepared for the first time with the process of continuous carbon coating and subsequent solution phase oxidation reaction. The self-supporting lithium-sulfur battery cathode material with high sulfur load has the loose, porous and super-thick structural characteristics, and high sulfur load and rapid ion transport are guaranteed. The three components, namely, the carbon-coated sulfur nanosheets, the carbon nanotubes and the bacterial cellulose, are entangled and connected, so that structural stability and high conductivity of the cathode material are further guaranteed.

Description

technical field [0001] The invention belongs to the field of preparation of battery cathode materials. Specifically, it relates to a zinc sulfide (diethylenetriamine) 0.5 A self-supporting, high-sulfur loading lithium-sulfur battery positive electrode material prepared from a hybrid nanosheet as a precursor and a preparation method thereof. Background technique [0002] Lithium-sulfur battery, as a new type of battery, has aroused widespread research interest and a lot of research because of its ultra-high theoretical capacity, abundant sulfur reserves, and low cost. However, in actual production, lithium-sulfur batteries still face several serious problems, namely, low conductivity of sulfur and corresponding sulfides, severe shuttle effect, and large volume change of the electrode during the lithium-deintercalation process of the sulfur cathode. The low discharge specific capacity and poor cycle stability further limit its commercial production and application. In this ...

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Problems solved by technology

However, in actual production, lithium-sulfur batteries still face several serious problems, namely, low conductivity of sulfur and corresponding sulfides, severe shuttle effect, and large volume change of the electrode during the lithium-deintercalation process of the sulfur cathode. Low discharge specific capacity and poor cycle stability further limit its commercial production and application

In this context, in order to further improve the performance of lithium-sulfur batteries, two general strategies have been proposed, namely: directly coating carbon-based or inorganic materials on the surface of nano-sulfur, and introducing highly conductive confined framework materials (physically confining polysulfides). However, the former is usually limited by the low electrical conductivity of carbon-based or inorganic materials, the sulfur content and spatial distribution, and the size of voids in the shell are difficult to precisely control. The latter adopts melting diffusion or The gas-phase perfusion method usually leads to unavoidable external residues and uneven distribution of sulfur, which further reduces its capacity and cycle stability.

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