Self-supporting lithium-sulfur battery cathode material, preparation method and application thereof

A technology for lithium-sulfur batteries and positive electrode materials, applied in battery electrodes, lithium batteries, positive electrodes, etc., can solve problems such as irreversible loss of active materials and capacity fading, damage to the structural stability of positive electrode materials, and affect battery stability. Shuttle effect, green and environmentally friendly technology, and the effect of improving cycle stability

Inactive Publication Date: 2018-05-29
WUHAN UNIV OF TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0003] However, lithium-sulfur batteries face many technical problems, such as the poor conductivity of sulfur, which seriously hinders the conduction of electrons; the shuttle effect generated during charging and discharging causes irreversible loss of active materials and attenuation of capacity; the volume of sulfur in the process of charging and discharging Expansion can easily cause the pulverization of the positive electrode material, destroying the structural stability of the positive electrode material and affecting the stability of the battery

Method used

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  • Self-supporting lithium-sulfur battery cathode material, preparation method and application thereof
  • Self-supporting lithium-sulfur battery cathode material, preparation method and application thereof
  • Self-supporting lithium-sulfur battery cathode material, preparation method and application thereof

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Embodiment 1

[0030] A self-supporting lithium-sulfur battery positive electrode material, the positive electrode material is graphene / sulfur sponge, the graphene / sulfur sponge has a rich porous structure similar to the sponge structure, the graphene / sulfur sponge is composed of graphene and The graphene sponge is composed of entangled sulfur particles.

[0031] A method for preparing a positive electrode material for a self-supporting lithium-sulfur battery, specifically comprising the following steps:

[0032] S100. Weigh 30 mg of graphene oxide and disperse it into 10 ml of deionized water, disperse evenly by ultrasonication for 1 hour, then add 120 mg of sodium thiosulfate pentahydrate, disperse evenly by ultrasonication, and obtain a mixed solution A;

[0033] S200. Under vigorous stirring, the mixed solution A is slowly dripped into dilute hydrochloric acid drop by drop with a syringe, and the dropping rate is controlled at 2 seconds per drop, until the pH value is 6.5-7, stop the dri...

Embodiment 2

[0040] A self-supporting lithium-sulfur battery positive electrode material, the positive electrode material is graphene / sulfur sponge, the graphene / sulfur sponge has a rich porous structure similar to the sponge structure, the graphene / sulfur sponge is composed of graphene and The graphene sponge is composed of entangled sulfur particles.

[0041] A method for preparing a positive electrode material for a self-supporting lithium-sulfur battery, specifically comprising the following steps:

[0042] S100. Weigh 30 mg of graphene oxide and disperse it into 10 ml of deionized water, disperse evenly by ultrasonication for 1 hour, then add 140 mg of sodium thiosulfate pentahydrate, disperse evenly by ultrasonication, and obtain a mixed solution A;

[0043] S200. Under vigorous stirring, the mixed solution A is slowly dripped into dilute hydrochloric acid drop by drop with a syringe, and the dropping rate is controlled at 2 seconds per drop, until the pH value is 6.5-7, stop the dri...

Embodiment 3

[0050] A self-supporting lithium-sulfur battery positive electrode material, the positive electrode material is graphene / sulfur sponge, the graphene / sulfur sponge has a rich porous structure similar to the sponge structure, the graphene / sulfur sponge is composed of graphene and The graphene sponge is composed of entangled sulfur particles.

[0051] A method for preparing a positive electrode material for a self-supporting lithium-sulfur battery, specifically comprising the following steps:

[0052] S100. Weigh 40 mg of graphene oxide and disperse it into 10 ml of deionized water, disperse evenly by ultrasonication for 1 hour, then add 120 mg of sodium thiosulfate pentahydrate, disperse evenly by ultrasonication, and obtain a mixed solution A;

[0053] S200. Under vigorous stirring, the mixed solution A is slowly dripped with dilute hydrochloric acid drop by drop with a syringe, and the dropping rate is controlled at 2 seconds per drop, until the pH value is 6.5-7, stop the dri...

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Abstract

The invention relates to a self-supporting lithium-sulfur battery cathode material and a preparation method and application thereof. The cathode material is prepared from graphene sponge and sulfur particles coated therein. The preparation method comprises the following specific steps: firstly dissolving sodium thiosulfate in dispersion liquid of commercial graphene oxide water, and then slowly dropping diluted hydrochloric acid during a stirring process to precipitate the sulfur particles on the surface of graphene oxide, then adding ascorbic acid, and stirring evenly and then reducing and assembling graphene under hydrothermal conditions to form a graphene / sulfur hydrogel, freeze-drying to obtain graphene / sulfur sponge, and sectioning and pressing to directly obtain the lithium-sulfur battery cathode material. The cathode material has a sponge-like structure, and the presence of macroporous mesopores facilitates the infiltration of an electrolyte and relieves the volume expansion ofsulfur in a charge-discharge process; and meanwhile, the graphene has a strong chemical adsorption effect on polysulfides to suppress the loss of the polysulfides, thus effectively improving the cycleperformance of the battery, and improving the specific capacity of the battery.

Description

technical field [0001] The invention relates to the field of lithium-sulfur batteries, in particular to a positive electrode material for a self-supporting lithium-sulfur battery and a preparation method and application thereof. Background technique [0002] With the depletion of fossil energy and the increasingly serious environmental problems and greenhouse effect, human beings must develop green energy to meet the growing energy demand. Lithium-ion batteries have high specific energy, no memory effect and good cycle stability, so they are widely used, and have occupied most of the market in various electronic products and electric vehicles. However, with the development of science and technology, human beings are no longer satisfied with the energy density of lithium-ion batteries, and begin to demand higher energy density battery systems. Lithium-sulfur battery has a high specific capacity (1675mAh / mg), which far exceeds the current commercial lithium-ion battery. In ad...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01M4/36H01M4/38H01M4/62H01M10/052
CPCH01M4/366H01M4/38H01M4/628H01M10/052H01M2004/021H01M2004/028Y02E60/10
Inventor 王洪恩魏现鹤李学成尹凯利赵传勇李念念李昱阳晓宇苏宝连
Owner WUHAN UNIV OF TECH
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