Sulfur-doped three-dimensional porous graphene/sulfur composite positive electrode material and preparation method and application thereof

A composite cathode material and three-dimensional porous technology, which is applied in nanotechnology for materials and surface science, battery electrodes, electrical components, etc., can solve problems such as poor cycle performance, low energy density, and long preparation process, and achieve high porosity High efficiency, large specific surface area, and the effect of improving utilization efficiency

Active Publication Date: 2017-05-10
CENT SOUTH UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0006] Aiming at the shortcomings of sulfur-doped three-dimensional graphene / sulfur composite cathode materials in the prior art, which generally exist in sulfur doping and low loading capacity, low energy density, poor cycle performance, and long preparation process, the first purpose of the present invention The purpose is to provide a sulfur-doped three-dimensional porous graphene / sulfur composite material with a large sulfur doping amount, a controllable loading amount, and uniform and stable loading

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  • Sulfur-doped three-dimensional porous graphene/sulfur composite positive electrode material and preparation method and application thereof
  • Sulfur-doped three-dimensional porous graphene/sulfur composite positive electrode material and preparation method and application thereof
  • Sulfur-doped three-dimensional porous graphene/sulfur composite positive electrode material and preparation method and application thereof

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Experimental program
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Effect test

Embodiment 1

[0037] After ultrasonicating 400mL of graphene oxide dispersion with a concentration of 2mg / L for 2 hours, add 1.6g of sodium bisulfite with stirring, raise the temperature to 50°C and keep it for 2 hours, take out a small amount of the reacted solution, wash it several times, pass through X X-ray photoelectron spectroscopy was used to characterize, and the results showed that the doping amount of sulfur accounted for 0.2%. Then add 4 g of sodium sulfide into the above reacted solution, and stir for 0.5 hour. The above solution was suction-filtered and washed 3 times with deionized water, and the filter cake was transferred to a freeze dryer to dry for 24 hours to obtain a sulfur-doped three-dimensional porous graphene / sulfur composite material. The actual sulfur content was obtained by thermogravimetric testing. 35 wt.%. Gained composite positive electrode material, conductive carbon black, polyvinylidene fluoride (PVDF) are uniformly mixed according to a mass ratio of 8:1:1...

Embodiment 2

[0040] After ultrasonicating 400mL of graphene oxide dispersion with a concentration of 5mg / L for 2 hours, stir and add 4g of sodium bisulfite, raise the temperature to 50°C and keep it for 2 hours, take out a small amount of the reacted solution, wash it several times, and pass X-ray Characterized by photoelectron spectroscopy, the results show that the doping amount of sulfur atoms accounts for 3%. Then add 7 g of sodium sulfide into the above reacted solution, and stir for 0.5 hour. The above solution was suction-filtered and washed 3 times with deionized water, and the filter cake was transferred to a freeze dryer to dry for 24 hours to obtain a sulfur-doped three-dimensional porous graphene / sulfur composite material. The actual sulfur content was obtained by thermogravimetric testing. 52.1 wt.%. Gained composite positive electrode material, conductive carbon black, polyvinylidene fluoride (PVDF) are uniformly mixed according to a mass ratio of 8:1:1, and dispersed in a c...

Embodiment 3

[0043] After ultrasonicating 400mL of graphene oxide dispersion with a concentration of 2mg / L for 2 hours, stir and add 6g of sodium bisulfite, raise the temperature to 50°C and keep it for 2 hours, take out a small amount of the reacted solution, wash it several times, and pass X-ray Characterized by photoelectron spectroscopy, the results show that the doping amount of sulfur accounts for 5% of atoms. Then add 8 g of sodium sulfide into the above reacted solution, and stir for 0.5 hour. The above solution was suction-filtered and washed 3 times with deionized water, and the filter cake was transferred to a freeze dryer to dry for 24 hours to obtain a sulfur-doped three-dimensional porous graphene / sulfur composite material. The actual sulfur content was obtained by thermogravimetric testing. 73.2 wt.%. Gained composite positive electrode material, conductive carbon black, polyvinylidene fluoride (PVDF) are uniformly mixed according to a mass ratio of 8:1:1, and dispersed in ...

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Abstract

The invention discloses a sulfur-doped three-dimensional porous graphene/sulfur composite positive electrode material and a preparation method and an application thereof. The sulfur-doped three-dimensional porous graphene/sulfur composite positive electrode material is composed of elemental sulfur deposited on a surface of a three-dimensional carbon skeleton of sulfur-doped three-dimensional porous graphene in situ; and the preparation method comprises the steps of first adding sodium bisulfate to a graphene oxide dispersion to react, then adding sodium sulfide to react under a partially neutral condition, carrying out liquid-solid separation, and performing freeze-drying on a solid product, thereby obtaining the sulfur-doped three-dimensional porous graphene/sulfur composite positive electrode material. A sulfur-doped amount of the composite positive electrode material is large, a sulfur loading capacity is controllable, a load is uniform and a utilization rate of an active substance sulfur is high; the sulfur-doped three-dimensional porous graphene/sulfur composite positive electrode material has the advantages of high specific capacity, high energy density, high stability and the like; and the cycle performance of a lithium-sulfur battery is greatly improved.

Description

technical field [0001] The invention relates to a lithium-sulfur battery cathode material, in particular to a sulfur-doped three-dimensional porous graphene / sulfur composite cathode material, a preparation method thereof, and an application of the composite cathode material in a flow battery, belonging to the field of lithium-sulfur batteries. Background technique [0002] With the widespread application of lithium-ion batteries in portable electronics, electric vehicles, and plug-in hybrid electric vehicles, there is an urgent need to develop batteries with higher energy density. As the specific capacity of lithium-ion battery cathode materials is limited, it is difficult to further increase the energy density of lithium-ion batteries. At the same time, increasing the energy density by increasing the voltage platform of the cathode material will bring safety problems. Changing the cathode material from the "deintercalation mechanism" to the "conversion reaction chemical me...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01M4/36H01M4/38H01M4/587H01M4/62H01M10/0525B82Y30/00
CPCB82Y30/00H01M4/362H01M4/38H01M4/587H01M4/624H01M4/625H01M4/628H01M10/0525Y02E60/10
Inventor 陈康华李娜甘芳瑜陈送义
Owner CENT SOUTH UNIV
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