Preparation method of carbon-based flexible lithium-sulfur battery cathode material of porous structure

Abstract

The invention relates to a preparation method of a carbon-based flexible lithium-sulfur battery cathode, belonging to the technical field of preparation of lithium-sulfur battery materials for electrochemical energy storage. The method comprises the following steps of: preparing a three-dimensional conductive carbon network by annealing carbon fibers in an oxidizing atmosphere, taking the three-dimensional conductive carbon fiber network as a current collector, immersing the three-dimensional conductive carbon fiber network into carbon disulfide of sulfur, soaking a carbon fiber hole structurewith a sulfur solution by ultrasonic waves or mechanical oscillation under vacuum, performing evaporating to dryness, and further diffusing the sulfur into finer gaps of the carbon fibers by high-temperature gas phase diffusion to form a carbon-based flexible lithium-sulfur battery cathode with the sulfur uniformly distributed in the three-dimensional conductive carbon fiber network. The flexiblebattery assembled by the self-supporting electrodes can keep high and stable charge and discharge capacity under different folding angles. The preparation method of the self-supporting flexible electrode is simple to operate and easy for large-scale production, is capable of being widely applied to energy storage and flexible wearable equipment, and is good in practical value.

Description

technical field [0001] The invention belongs to the technical field of preparation of lithium-sulfur battery materials, and in particular relates to a preparation method of a porous carbon-based flexible lithium-sulfur battery cathode material. Background technique [0002] With the improvement of people's material and cultural needs and the rapid development of science and technology, convenient and lightweight portable wearable electronic products have been greatly loved by people, including flexible, bendable and foldable displays, electronic paper, flexible batteries, etc. Therefore, there will be huge market demand and space for portable, wearable, flexible and lightweight energy storage devices, and there will be great room for development as lithium-ion batteries with high energy density, strong safety, and easy portability. At present, the energy density of traditional lithium-ion batteries such as lithium cobalt oxide, lithium manganese oxide, lithium iron phosphate...

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to solve the problems that the traditional lithium-sulfur battery cannot be folded and bent, the conductivity of the sulfur active material is poor, the volume of the sulfur electrode rapidly expands and deforms after lithium intercalation, and the lithium polysulfide intermediate product generated during the discharge process is easily soluble in the electrolyte. Provided is a method for preparing a porous carbon-based flexible lithium-sulfur battery positive electrode material

[0005] In the present invention, a three-dimensional carbon-based conductive fiber network with a certain strength is selected as the carrier and conductive network of the positive electrode material of the flexible lithium-sulfur battery, and the sulfur active material is evenly dispersed in the porous network of the conductive fiber network through the method of dissolution recrystallization and high-temperature diffusion In the structure, it solves the problem that the cathode material of conventional lithium-sulfur batteries cannot be bent and folded

Images