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Lithium-sulfur battery separator and preparation method thereof, lithium-sulfur battery and preparation method thereof

A lithium-sulfur battery and diaphragm technology, applied in the field of diaphragm, can solve the problems of unstoppable dissolution and shuttle of polysulfide, loss of positive active material, and reduction of Coulombic efficiency of the system, so as to suppress the shuttle effect, reduce the resistance of the interface reaction, and improve the circulation performance effect

Active Publication Date: 2021-06-25
GREAT POWER BATTRY ZHUHAI
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

However, the reaction system of lithium-sulfur batteries is very complicated. During the charging and discharging process, the lithium polysulfide intermediate product dissolves in the electrolyte, which will cause the loss of positive active materials and lead to battery capacity attenuation. At the same time, polysulfides will oxidize with metal lithium after reaching the negative electrode. Reduction reaction, forming a "shuttle effect", reducing the Coulombic efficiency of the system
However, in order to ensure a high lithium ion conductivity, the current commercial polyethylene or polypropylene separator has a relatively high porosity and a large pore diameter, while the diameter of polysulfide ions is less than 1nm, so the traditional separator is for Polysulfide ions basically have no blocking effect and cannot block the dissolution and shuttling of polysulfides

Method used

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  • Lithium-sulfur battery separator and preparation method thereof, lithium-sulfur battery and preparation method thereof
  • Lithium-sulfur battery separator and preparation method thereof, lithium-sulfur battery and preparation method thereof
  • Lithium-sulfur battery separator and preparation method thereof, lithium-sulfur battery and preparation method thereof

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preparation example Construction

[0064] In a preferred embodiment of the present invention, the preparation method of nitrogen-doped porous carbon-carbon nanotube-graphene material comprises the following steps:

[0065] The amine group-modified nanoporous carbon, carboxylated graphene and carboxylated carbon nanotubes are mixed and subjected to condensation reaction to obtain nitrogen-doped porous carbon-carbon nanotube-graphene.

[0066] In a further preferred embodiment of the present invention, after mixing amine group modified nanoporous carbon, carboxylated graphene and carboxylated carbon nanotubes, a condensation reaction activator is added to speed up the condensation reaction process to obtain nitrogen-doped porous carbon-carbon Nanotubes - Graphene.

[0067] In a preferred embodiment of the present invention,

[0068] In a further preferred embodiment of the present invention, amine modified nanoporous carbon, carboxylated graphene and carboxylated carbon nanotubes are placed in a reaction flask, ...

Embodiment 1

[0110] This embodiment provides a lithium-sulfur battery separator. The separator is composed of a polypropylene porous film with a thickness of 25 μm as a support film and a nitrogen-doped carbon adsorption-conductive coating with a thickness of 5 μm. The preparation method includes the following steps:

[0111] The nitrogen-doped porous carbon-carbon nanotube-graphene and polyvinylidene chloride binder were added to N-methylpyrrolidone in a mass ratio of 9:1 to make a slurry, and then the slurry was coated on the surface of the support film , and after drying, a composite separator for a lithium-sulfur battery separator is obtained.

[0112] Wherein, nitrogen-doped porous carbon-carbon nanotube-graphene is prepared according to the following steps:

[0113] The amine group-modified nanoporous carbon, carboxylated single-layer graphene and carboxylated double-walled carbon nanotubes were dispersed in a toluene solution in a mass ratio of 1:2:1, activated by adding DCC, and he...

Embodiment 2

[0120] This embodiment provides a lithium-sulfur battery separator. The separator is composed of a polyethylene porous film with a thickness of 25 μm as a supporting film and a nitrogen-doped carbon adsorption-conductive coating with a thickness of 10 μm. The preparation method is the same as that of Example 1. The same, the difference is that nitrogen-doped porous carbon-carbon nanotube-graphene is made of amine-modified nanoporous carbon, carboxylated double-layer graphene and carboxylated single-walled carbon nanotubes according to the mass 1:2:1, Among them, the amine group modified nanoporous carbon adopts Ketjen black and acetylene black (mass ratio 1:1) as the source of nanoporous carbon material.

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Abstract

The invention provides a lithium-sulfur battery diaphragm and a preparation method thereof, a lithium-sulfur battery and a preparation method thereof, and relates to the field of diaphragm technology. The lithium-sulfur battery diaphragm includes a support film, and the support film is compounded with nitrogen-doped carbon adsorption- Conductive coating, the preparation method of the lithium-sulfur battery diaphragm includes the following steps: coating the nitrogen-doped carbon adsorption-conductive coating on the support film, and after drying, the lithium-sulfur battery diaphragm is obtained, which alleviates the traditional diaphragm for polysulfide Ions basically have no blocking effect, and cannot block the technical problem of polysulfide dissolution and shuttling phenomenon. By compounding a nitrogen-doped carbon adsorption-conductive coating on the support membrane, polysulfide can be adsorbed on the diaphragm for strong Conductivity transformation, inhibit the "shuttle effect" of polysulfides, reduce the resistance of the interface reaction, effectively recover the dissolved sulfur at the interface between the positive electrode and the separator, improve the utilization rate of positive active materials, limit the transmembrane diffusion of polysulfides, and thus improve lithium Cycle performance of sulfur batteries.

Description

technical field [0001] The invention relates to the technical field of separators, in particular to a lithium-sulfur battery separator and a preparation method thereof, a lithium-sulfur battery and a preparation method thereof. Background technique [0002] With the increasing energy crisis and environmental pollution, rechargeable batteries with excellent performance have become one of the important means to solve the above problems. Lithium-ion batteries have the advantages of better cycle life, higher operating voltage and less pollution, so lithium-ion batteries have been more and more widely used. However, issues such as low battery energy density, high battery cost, and battery safety limit the application of lithium-ion batteries in electric vehicles and large-scale energy storage devices. Researching high-performance batteries with high energy density, long cycle life, good safety, and low cost has become a top priority. In order to meet the needs of society, the d...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H01M50/417H01M50/403H01M10/052H01M10/0587C01B32/05H01M50/431H01M50/491H01M50/497
CPCH01M10/052H01M10/0587C01B32/05H01M50/431H01M50/403H01M50/411H01M50/449Y02E60/10Y02P70/50
Inventor 黄雪妍薛建军孟跃中肖敏王拴紧
Owner GREAT POWER BATTRY ZHUHAI