Positive electrode of lithium sulfur battery and preparation method thereof

A lithium-sulfur battery and positive electrode technology, which is applied in the field of new energy, can solve the problems of poor electronic conductivity and ionic conductivity of electrode sheets, lower discharge efficiency, and increased battery internal resistance, so as to achieve better conductivity and smaller interface impedance , the effect of reducing internal resistance

Active Publication Date: 2012-07-11
CENT SOUTH UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0005] In addition, if the active slurry is directly coated on the current collector, the interface impedance will be large, resulting in poor electronic conductivity and ion conductivity of the electrode sheet.
When the adhesion between th

Method used

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  • Positive electrode of lithium sulfur battery and preparation method thereof
  • Positive electrode of lithium sulfur battery and preparation method thereof
  • Positive electrode of lithium sulfur battery and preparation method thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0037] Mix elemental sulfur, conductive graphite and polytetrafluoroethylene uniformly at a mass ratio of 10:80:10, disperse them in an aqueous solution, and carry out sufficient mechanical stirring to obtain a carbon-coated slurry; evenly scrape the slurry on an aluminum foil current collector Above, after vacuum drying at 120°C, press to obtain a carbon-coated current collector, and the thickness of the carbon-coated layer is 30 μm;

[0038] The sulfur-carbon nanotube composite material, conductive carbon black and polytetrafluoroethylene are mechanically stirred and mixed uniformly at a mass ratio of 80:10:10, dispersed in an aqueous solution, and stirred to obtain a positive electrode active layer slurry; the slurry is scraped On the carbon-coated current collector, dry at 60° C. and then press to obtain the positive electrode sheet of the lithium-sulfur battery, wherein the thickness of the active layer is 150 μm.

[0039] Electrochemical performance test:

[0040] The p...

Embodiment 2

[0042] Mix elemental sulfur, acetylene black, and polyvinylidene fluoride uniformly at a mass ratio of 1:80:19, disperse them in N-methylpyrrolidone solution, and carry out sufficient mechanical stirring to obtain carbon-coated slurry; uniformly print the slurry On the aluminum foil current collector, after vacuum drying at 100°C, press to obtain a carbon-coated current collector, and the thickness of the carbon-coated layer is 200nm;

[0043]Elemental sulfur, conductive carbon black and polytetrafluoroethylene were mechanically stirred and mixed uniformly in a mass ratio of 70:20:10, dispersed in an aqueous solution, and stirred to obtain a positive electrode active layer slurry; the slurry was rolled onto a carbon-coated surface On the current collector, after drying at 70°C, press to obtain the positive electrode sheet of the lithium-sulfur battery, wherein the thickness of the active layer is 90 μm.

[0044] Electrochemical performance test:

[0045] The positive electrod...

Embodiment 3

[0047] Mix elemental sulfur, acetylene black, and polyvinylidene fluoride uniformly at a mass ratio of 10:70:20, disperse them in N-methylpyrrolidone solution, and carry out sufficient mechanical stirring to obtain carbon-coated slurry; scrape the slurry On the aluminum foil current collector, after vacuum drying at 110°C, press to obtain a carbon-coated current collector, and the thickness of the carbon-coated layer is 600nm;

[0048] Mix sulfur-carbon nanotube composite material, conductive carbon black, and polyvinylidene fluoride with mechanical stirring at a mass ratio of 80:10:10, disperse them in N-methylpyrrolidone solution, and perform mechanical stirring to obtain positive active layer slurry ; Scrape-coat the slurry on the carbon-coated current collector, dry it at 70° C. and press it to obtain the positive electrode sheet of the lithium-sulfur battery, wherein the thickness of the active layer is 150 μm.

[0049] Electrochemical performance test:

[0050] The posi...

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Abstract

The invention discloses a positive electrode of a lithium sulfur battery and a preparation method of the positive electrode of the lithium sulfur battery. The positive electrode of the lithium sulfur battery comprises two parts, namely a carbon coating layer with low-active substance content on a current collector and an active layer with high-active substance content. The carbon coating layer on the surface of the current collector can improve the corrosion resistance of the current collector and prevent the current collector from being oxidized or corroded chemically. The positive electrode with the structure reduces the interface impedance of the current collector and the active layer, the electric conduction of the positive electrode of the battery is enhanced, and the volume volatilization of active substance materials is facilitated. The positive electrode with the structure is applied to the lithium sulfur battery, beneficial to the reduction of the internal resistance of the battery, prolongs to the cycle life of the battery and improves the multiplying power property of the battery.

Description

technical field [0001] The invention belongs to the field of new energy, and relates to a positive electrode of a lithium-sulfur battery and a preparation method thereof, in particular to an improvement in the structure of the positive electrode. Background technique [0002] With the increasing shortage of traditional resources and energy and the increasingly serious environmental problems, the development of new energy storage and conversion technologies has become the focus of energy strategies of various countries. Among them, lithium-sulfur batteries are high-energy-density secondary batteries with great development potential and application prospects. It has high specific capacity (1675mAh / g) and high energy density (2600Wh / kg). In addition, sulfur as an active material also shows incomparable advantages in terms of cost and environmental friendliness. [0003] Lithium-sulfur battery cathodes are usually obtained by dispersing sulfur-containing materials, conductive ...

Claims

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Application Information

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IPC IPC(8): H01M4/62H01M4/13H01M4/139
CPCY02E60/122Y02E60/10
Inventor 张治安邓兆丰卢海章智勇贾明赖延清刘晋李劼刘业翔
Owner CENT SOUTH UNIV
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