Sulfur-carbon compound and preparation method therefor, and electrode material and lithium-sulfur battery containing sulfur-carbon compound

A technology of sulfur-carbon composites and lithium-sulfur batteries, applied in the field of lithium-ion batteries, can solve problems such as hindering practical applications, changes in shape and structure, and reducing ion conductivity, so as to avoid electrochemical intermediate reactions and the preparation method is simple and easy Line, prevent the effect of the shuttle effect

Inactive Publication Date: 2016-05-04
MCNAIR TECH +2
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0003] However, there are still some problems hindering its practical application in lithium-sulfur batteries. The specific problems are as follows: 1. The electronic conductivity and ionic conductivity of elemental sulfur are poor, and the conductivity of sulfur materials at room temperature is extremely low (5.0×10 -30 S cm -1 ), the final product of the reaction Li 2 S 2 and Li 2 S is also an electronic insulator, which is not conducive to the high rate performance of the battery; 2. Lithium polysulfides, the intermediate discharge products of lithium-sulfur batteries, will dissolve into the organic electrolyte, increase the viscosity of the electrolyte, and reduce the ion conductivity; and lithium polysulfides It can migrate between the positive and negative electrodes, resulting in the loss of active materials and the waste of electric energy; and the dissolved lithium polysulfides will diffuse across the separator to the negative electrode, react with the negative electrode, and destroy the solid electrolyte interface film (SEI film) of the negative electrode; 3. The final discharge product of lithium-sulfur batteries, Li 2 S n (n=1~2) Electronic insulation and insoluble in organic electrolyte

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  • Sulfur-carbon compound and preparation method therefor, and electrode material and lithium-sulfur battery containing sulfur-carbon compound
  • Sulfur-carbon compound and preparation method therefor, and electrode material and lithium-sulfur battery containing sulfur-carbon compound
  • Sulfur-carbon compound and preparation method therefor, and electrode material and lithium-sulfur battery containing sulfur-carbon compound

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preparation example Construction

[0047] When the above-mentioned sulfur-carbon composite is prepared, the key lies in the carbon nanoparticles, and its preparation method includes the following steps:

[0048] 11) Provide an aqueous suspension of nano-scale Na-X zeolite, drop strong acid thereinto until the aqueous suspension becomes clear, and obtain an aqueous solution;

[0049] 12) after the ethanol solution of described aqueous solution and phenolic resin is mixed, then react with strong ammonia water, evaporate to dryness solvent (water and ethanol) after reaction is complete, obtain the mixture of carbon nanometer precursor and templating agent;

[0050] 13) carbonizing the mixture of the carbon nano precursor and the template in a protective atmosphere to obtain primary carbon nanoparticles,

[0051] 14) Pickling the primary carbon nanoparticles until the content of the silica template is 1 wt% to 5 wt%, to obtain the carbon nanoparticles.

[0052] In the preparation of carbon nanoparticles, nano-scal...

Embodiment 1

[0063] A kind of sulfur-carbon compound, its preparation method comprises the steps:

[0064]In the first step, take 4 g of the nano-Na-X zeolite with a size of 40 nm prepared by the above method and disperse it in 20 mL of deionized water, add 6 M concentrated hydrochloric acid dropwise, and stir while adding until a clear and translucent aqueous solution is obtained;

[0065] The second step is to prepare carbon nanoparticles: mix the above aqueous solution with 70ml of ethanol solution containing 3wt% phenolic resin, and stir at 50°C to obtain a mixed solution; mix 30mL of concentrated ammonia water with 100mL of ethanol, add the above mixed solution, and stir at 50°C 3h, followed by stirring and evaporating to dryness at 60° C., removing the solvent (ethanol and water) to obtain a mixture of carbon nano precursor and template;

[0066] The third step is to carbonize the mixture of carbon nano-precursor and template agent in a protective atmosphere above 850°C, and then rem...

Embodiment 2

[0070] A kind of sulfur-carbon compound, its preparation method comprises the steps:

[0071] In the first step, take 4 g of the nano-Na-X zeolite with a size of 20 nm prepared by the above method and disperse it in 20 mL of deionized water, add 8 M concentrated hydrochloric acid dropwise, and stir while adding until a clear and translucent aqueous solution is obtained;

[0072] The second step is to prepare carbon nanoparticles: mix the above aqueous solution with 80ml ethanol solution containing 3wt% phenolic resin, and stir at 50°C to obtain a mixed solution; mix 30mL concentrated ammonia water with 100mL ethanol, add the above mixed solution, and stir at 50°C 3h, followed by stirring and evaporating to dryness at 60° C., removing the solvent (ethanol and water) to obtain a mixture of carbon nano precursor and template;

[0073] The third step is to carbonize the mixture of carbon nano-precursor and template agent in a protective atmosphere above 850°C, and then remove the ...

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Abstract

The invention relates to the technical field of a lithium ion battery, and particularly to a sulfur-carbon compound for a lithium-sulfur battery. The sulfur-carbon compound comprises carbon nanoparticles, sulfur loaded in the carbon nanoparticles and silicon dioxide template existing in the carbon nanoparticles in a residual manner, wherein the content of sulfur accounts for 40-70% of the content of the sulfur-carbon compound based on mass percent; and the content of the silicon dioxide template accounts for 0.3-3% of the content of the sulfur-carbon compound based on mass percent. The residual silicon dioxide template in the sulfur-carbon compound is dispersed in the carbon nanoparticles so as to reduce the aperture of the carbon nanoparticles; therefore, the carbon nanoparticles have a relatively high capture capability for polysulfide lithium that is an intermediate product of an electrochemical reaction in use; meanwhile, the residual silicon dioxide template can effectively prevent a flying shuttle effect of polysulfide lithium; and the invention also relates to a preparation method for the sulfur-carbon compound, and an electrode material and the lithium-sulfur battery containing the sulfur-carbon compound.

Description

technical field [0001] The invention relates to the technical field of lithium-ion batteries, in particular to a sulfur-carbon composite for lithium-sulfur batteries, a preparation method thereof, an electrode material prepared by using the sulfur-carbon composite, and a lithium-sulfur battery. Background technique [0002] Lithium-sulfur battery is a kind of lithium battery, which is a secondary battery with metal lithium as the negative electrode and sulfur element as the positive electrode; when the lithium-sulfur battery is discharged, the negative electrode reaction is that lithium loses electrons and becomes lithium ions, and the positive electrode reaction is sulfur and lithium. Ions and electrons react to form sulfides, and the potential difference between the positive and negative electrodes is the discharge voltage provided by the lithium-sulfur battery. The specific energy of lithium-sulfur batteries can theoretically reach 2600Wh / kg, which is far greater than any...

Claims

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Application Information

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IPC IPC(8): H01M4/36H01M4/38H01M4/62H01M10/052B82Y30/00B82Y40/00
CPCB82Y30/00B82Y40/00H01M4/364H01M4/38H01M4/625H01M10/052Y02E60/10
Inventor 崔彦辉武俊伟常嵩郑新宇张新河李中延屈德扬
Owner MCNAIR TECH
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