A kind of bioporous carbon-based lithium-sulfur battery cathode material and preparation method thereof

A technology of positive electrode material and porous carbon, which is applied in the field of biological porous carbon-based lithium-sulfur battery positive electrode materials and its preparation, can solve the problems of destroying the structural stability of positive electrode materials, affecting the specific capacity and stability of batteries, and reducing the cycle stability of batteries. , to achieve excellent electrochemical performance, increase binding energy, and increase the effect of micropore content

Active Publication Date: 2020-04-21
WUHAN UNIV OF TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] But at present, lithium-sulfur batteries still face many technical problems: first, the insulation of elemental sulfur seriously affects electron conduction; second, during the charging and discharging process, a part of the intermediate product lithium polysulfide is easily soluble in the electrolyte, and shuttles back and forth between positive and negative. It is easy to have a side reaction with the negative electrode lithium and deposit on the lithium sheet, which is the so-called "shuttle effect", which reduces the cycle stability of the battery; third, in the process of charging and discharging, the cyclic S in the positive electrode material 8 Dissolved in the electrolyte solution to open the ring to become a long chain Li 2 S 6 , volume expansion will occur, and the expansion rate reaches 80%, which will seriously damage the structural stability of the positive electrode material and affect the specific capacity and stability of the battery.

Method used

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  • A kind of bioporous carbon-based lithium-sulfur battery cathode material and preparation method thereof
  • A kind of bioporous carbon-based lithium-sulfur battery cathode material and preparation method thereof
  • A kind of bioporous carbon-based lithium-sulfur battery cathode material and preparation method thereof

Examples

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Embodiment 1

[0044] A bioporous carbon-based lithium-sulfur battery cathode material, the preparation method of which comprises the following steps:

[0045] 1) Take natural hickory shells and use deionized water to ultrasonically wash away the surface dust for 30 minutes, then add 0.2mol / L dilute hydrochloric acid and soak for 2 hours to remove the minerals on the surface of the walnut shells; then wash with absolute ethanol to remove the surface of the walnut shells organic matter, and then moved to an oven at 120°C for 24 hours;

[0046] 2) Crushing the walnut shells obtained in step 1) to obtain walnut slices with a size of 0.5-1 cm, and then taking 5 g of the obtained walnut slices, placing them in a crucible and heating to 700 ° C in a tube furnace under an argon atmosphere for carbonization 2 hours to get biocoke, the heating rate is 3°C / min;

[0047] 3) Take 2g of the obtained biocoke and 8g of KOH, grind and mix them evenly, place them in a corundum boat and activate them in a tu...

Embodiment 2

[0057] A bioporous carbon-based lithium-sulfur battery cathode material, the preparation method of which comprises the following steps:

[0058] 1) Take natural hickory shells and use deionized water to ultrasonically wash away the surface dust for 30 minutes, then add 0.2mol / L dilute hydrochloric acid and soak for 2 hours to remove the minerals on the surface of the walnut shells; then wash with absolute ethanol to remove the surface of the walnut shells organic matter, and then moved to an oven at 120°C for 24 hours;

[0059] 2) Crushing the walnut shells obtained in step 1) to obtain walnut slices with a size of 0.5-1 cm, then taking 5 g of the obtained walnut slices, placing them in a crucible and heating them to 680°C in a tube furnace under an argon atmosphere for carbonization 2 hours to get biocoke, the heating rate is 3°C / min;

[0060] 3) Take 3g of the obtained biocoke and 12g of KOH, grind and mix them evenly, place them in a corundum boat and activate them in a tu...

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PUM

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Abstract

The invention discloses a biological porous carbon-based cathode material of a lithium-sulphur battery. By taking a walnut shell as a biological carbon source, the walnut shell is subjected to thermal pyrolysis at a high temperature to obtain a bio-coke; and then activation reaction on the bio-coke is carried out by adopting KOH, so that microporous channels are effectively enriched and the mesopore size is adjusted. The obtained microporous bio-carbon material has extremely high specific surface and has a developed pore structure; after the material is supported with sulphur, excellent electrochemical performance and stability can be shown; moreover, the sources of the related raw materials are wide, the preparation process is simple, and the material is suitable for being popularized and applied.

Description

technical field [0001] The invention belongs to the technical field of lithium-sulfur batteries, and relates to a biological porous carbon-based lithium-sulfur battery cathode material and a preparation method thereof. Background technique [0002] Biochar is a solid product produced by high temperature pyrolysis of biological organic materials (biomass) in an anoxic or anaerobic environment. It can be used as a high-quality energy material, and its sources can be seen everywhere. If biochar is used to turn waste into treasure, it will not only alleviate the energy shortage, but also provide a certain solution to climate change and environmental pollution to a certain extent. The developed biochar The pore structure has good application prospects in the field of lithium-sulfur batteries. [0003] But at present, lithium-sulfur batteries still face many technical problems: first, the insulation of elemental sulfur seriously affects electron conduction; second, during the cha...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C01B32/324C01B32/348C01B17/22H01M4/583H01M4/587H01M10/052
CPCC01B17/22C01P2002/72C01P2004/03C01P2004/04C01P2006/17H01M4/583H01M4/587H01M10/052H01M2004/021H01M2004/028Y02E60/10
Inventor 陈丽华吴攀蔡昌蔡棋冯文静肖珊珊
Owner WUHAN UNIV OF TECH
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