A kind of sulfur-graphene composite cathode material and preparation method thereof

A composite cathode material, graphene composite technology, applied in battery electrodes, electrical components, circuits, etc., can solve the problems of low sulfur ion conductivity and electronic conductivity, decreased battery cycle charge and discharge performance, and poor sulfur electrochemical performance. , to achieve the effect of good conductivity, abundant raw materials and low price

Active Publication Date: 2011-12-14
INST OF PROCESS ENG CHINESE ACAD OF SCI
View PDF3 Cites 18 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] When lithium-sulfur batteries use sulfur as the positive electrode material, due to the low ionic conductivity and electronic conductivity of sulfur, the electrochemical performance of sulfur in the electrode is poor and the utilization rate is low. Lithium sulfide is irreversibly dissolved in the electrolyte and the dispersed sulfur particles agglomerate
In addition, the conductive structure of the electrode will change during the charge and discharge process, and these factors will cause the cycle charge and discharge performance of the battery to decrease and the specific capacity to decrease.

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • A kind of sulfur-graphene composite cathode material and preparation method thereof
  • A kind of sulfur-graphene composite cathode material and preparation method thereof

Examples

Experimental program
Comparison scheme
Effect test

preparation example Construction

[0024] 1) Preparation of composite electrode sheet: The sulfur-graphene composite material, the conductive agent acetylene black and the binder polyvinylidene fluoride (PVDF) were mixed in N-methyl-2-pyrrolidone ( Stir evenly in NMP) solvent, then coat it on an aluminum foil, dry it in vacuum at 60°C for 24 hours, and punch it into a 0.785cm 2 pole piece.

[0025] 2) Battery assembly: the composite electrode sheet prepared by the above method is used as the positive electrode, the metal lithium sheet is used as the negative electrode, and 1M LiClO 4 / PC is an organic electrolyte, which is assembled into a button cell in a glove box filled with argon.

[0026] 3) Battery test: The electrochemical performance test of the button battery assembled by the above method was carried out under the conditions of a current density of 100mA / g and a charging and discharging voltage of 1.5-4.2V.

Embodiment 1

[0029] Add 80wt% elemental sulfur and 20wt% graphene into the ball mill jar, then add 10ml of absolute ethanol and mill at a speed of 200r / min for 0.5h in a high-energy ball mill to mix the raw materials evenly, and then vacuum dry at 80°C for 1h. Put the dried material into a nitrogen-protected quartz sealed tube, then put the quartz sealed tube into a tubular heating furnace and heat it to 150 °C at a heating rate of 5 °C / min and keep it for 10 h, then cool naturally to room temperature to obtain sulfur- Graphene composite cathode material. The sulfur-graphene composite positive electrode material assembled battery obtained in this example has an initial discharge specific capacity of 1080 mAh / g at a charge and discharge current density of 100 mA / g, and the discharge specific capacity remains at 723 mAh / g after 50 cycles.

Embodiment 2

[0031] Add 98wt% elemental sulfur and 2wt% graphene into the ball mill jar, then add 5ml of absolute ethanol and mill at a speed of 500r / min in a high-energy ball mill for 1h to mix the raw materials evenly, and then vacuum dry at 80°C for 2h. Put the dried material into a quartz boat, then put it into a nitrogen-protected quartz sealed tube, and then put the quartz sealed tube into a tubular heating furnace to heat to 160 °C at a heating rate of 3 °C / min and keep it warm 24h, naturally cooled to room temperature to obtain sulfur-graphene composite cathode material. The battery assembled with the sulfur-graphene composite cathode material obtained in this example has an initial discharge specific capacity of 1212 mAh / g at a charge and discharge current density of 100 mA / g, and the discharge specific capacity remains at 752 mAh / g after 50 cycles.

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

No PUM Login to view more

Abstract

The invention relates to the field of electrochemistry and new energy materials and in particular relates to a sulphur-graphene composite cathode material and a manufacturing method thereof. The material provided by the invention comprises 80-98wt% of element sulfur and 2-20wt% of grapheme. The manufacturing method comprises the following steps: mixing 80-98wt% of element sulfur with 2-20wt% of graphene, and adding dispersing agents and carrying out ball milling as well as carrying out vacuum drying for 1-2 hours at the temperature of 80-100 DEG C; placing into a vacuum sealing device or sealing device filled with inert gases, putting the sealing device into a tubular heater, heating to 150-160 DEG C and performing heat preservation for 10-24 hours; and then cooling to room temperature so as to obtain the sulphur-graphene composite cathode material. According to the invention, the composite material manufactured by using the graphene has the advantages of low price, light weight and good electric conductivity; and simultaneously, the raw materials are rich, the process is simple, the operation is easy and the mass production can be realized easily.

Description

technical field [0001] The invention relates to the field of electrochemistry and new energy materials, in particular, the invention relates to a sulfur-graphene composite cathode material and a preparation method thereof. Background technique [0002] Lithium-ion battery cathode materials have always been the bottleneck restricting the development of lithium-ion batteries. Its price, specific capacity, rate charge and discharge performance, and cycle performance all need to be further optimized to meet the needs of large-scale high-power power sources such as aerospace and power vehicles. Among them, elemental sulfur is a high specific energy battery material, so elemental sulfur composite materials are an important research field in high-capacity cathode materials. [0003] When lithium-sulfur batteries use sulfur as the positive electrode material, due to the low ionic conductivity and electronic conductivity of sulfur, the electrochemical performance of sulfur in the el...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
Patent Type & Authority Applications(China)
IPC IPC(8): H01M4/38H01M4/139
CPCY02E60/122Y02E60/12Y02E60/10
Inventor 谭强强邱琳琳
Owner INST OF PROCESS ENG CHINESE ACAD OF SCI
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap