Lithium-sulfur battery containing barrier layer

A lithium-sulfur battery and barrier layer technology, applied in the field of electrochemical batteries, can solve the problems such as the barrier layer is not easy to peel off, waste, etc., and achieve the effects of improving electrochemical performance, easy operation, and improving electrical conductivity.

Inactive Publication Date: 2016-03-23
BEIJING INSTITUTE OF TECHNOLOGYGY
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to provide a preparation method of a lithium-sulfur battery containing a barrier layer in order to solve the problem that the existing barrier layer is not easy to peel off and cause waste

Method used

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  • Lithium-sulfur battery containing barrier layer
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  • Lithium-sulfur battery containing barrier layer

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0020] Pretreatment of aluminum foil current collector:

[0021] Cut the aluminum foil to a certain size and spread it on a clean glass plate, wash it repeatedly with ethanol and dry it at room temperature before use.

[0022] Preparation of positive electrode sheet:

[0023] The positive electrode active material sulfur, the conductive agent, and the N-methylpyrrolidone (NMP) solution of polyvinylidene fluoride (PVDF) were used as a binder, and mixed at a mass ratio of 7:2:1. Stir on a magnetic stirrer for 8 hours to obtain a viscous slurry; apply the viscous slurry evenly on the current collector, and then dry it in a vacuum oven at 50°C for 20 hours to obtain a positive pole piece.

[0024] The preparation method of bacterial cellulose derivatized carbon fiber barrier layer is:

[0025] The bacterial cellulose hydrogel was cut into small pieces with a blade, washed several times with deionized water, and then soaked in deionized water for 1 day. The bacterial cellulose w...

Embodiment 2

[0032] Pretreatment of aluminum foil current collector:

[0033] Cut the aluminum foil to a certain size and spread it on a clean glass plate, wash it repeatedly with ethanol and dry it at room temperature before use.

[0034] Preparation of positive electrode sheet:

[0035] The positive electrode active material sulfur, the conductive agent, and the N-methylpyrrolidone (NMP) solution of polyvinylidene fluoride (PVDF) were used as a binder, and mixed at a mass ratio of 7:2:1. Stir on a magnetic stirrer for 8 hours to obtain a viscous slurry; apply the viscous slurry evenly on the current collector, and then dry it in a vacuum oven at 50°C for 20 hours to obtain a positive pole piece.

[0036] The preparation method of activated carbon barrier layer is:

[0037]Disperse the activated carbon in the ethanol solution, place the PVDF membrane in the Millipore ultrafiltration cup, then pour the dispersed activated carbon suspension into the ultrafiltration cup, and adjust the gas...

Embodiment 3

[0043] Pretreatment of aluminum foil current collector:

[0044] Cut the aluminum foil to a certain size and spread it on a clean glass plate, wash it repeatedly with ethanol and dry it at room temperature before use.

[0045] Preparation of positive electrode sheet:

[0046] The positive electrode active material sulfur, the conductive agent, and the N-methylpyrrolidone (NMP) solution of polyvinylidene fluoride (PVDF) were used as a binder, and mixed at a mass ratio of 7:2:1. Stir on a magnetic stirrer for 8 hours to obtain a viscous slurry; apply the viscous slurry evenly on the current collector, and then dry it in a vacuum oven at 50°C for 20 hours to obtain a positive pole piece.

[0047] The preparation method of barrier layer is:

[0048] Disperse the graphite powder in the ethanol solution, place the PVDF membrane in the Millipore ultrafiltration cup, then pour the dispersed graphite powder suspension into the ultrafiltration cup, and adjust the gas pressure of the u...

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Abstract

The invention relates to a lithium-sulfur battery containing a barrier layer, and belongs to the field of electrochemical batteries. The surface of the positive electrode of a conventional lithium-sulfur battery is coated with a bacterial cellulose derived carbon fiber barrier layer, so that the dissolution, shuttling and battery negative electrode corrosion of polysulfide in an electrolyte solution of the lithium-sulfur battery during charging / discharging are inhibited. According to the lithium-sulfur battery containing the barrier layer, a carbon material is directly pressed on the surface of a membrane by utilizing external pressure through using an ultra-filtration cup, and the membrane is directly used after being dried without the need for stripping the carbon-containing barrier layer, so that the material waste is avoided and the effectiveness and completeness of the barrier layer are ensured. The bacterial cellulose derived carbon fiber barrier layer improves the conductive problem of sulfur as an active substance of the positive electrode of the lithium-sulfur battery, and the three-dimensional space structure of carbon fibers also provides a buffer space for volume expansion during charging / discharging, so that the electrode collapse is prevented and the electrochemical performance of the lithium-sulfur battery is improved. Under the current density of 0.5C, the initial discharge specific capacity of the battery is 1,823.2mAh / g, and the specific discharge capacity of the battery after being cycled for 100 times is 939.4mAh / g.

Description

technical field [0001] The invention relates to a lithium-sulfur battery containing a barrier layer, which belongs to the field of electrochemical batteries. Background technique [0002] Today in the 21st century, lithium secondary batteries are facing higher requirements for high energy density. A lithium-sulfur battery is a secondary battery in which elemental sulfur is used as the positive electrode and metallic lithium is used as the negative electrode. Compared with traditional lithium-ion batteries, lithium-sulfur batteries have a very obvious advantage in theoretical capacity, with a theoretical capacity as high as 1675mAh / g. Moreover, elemental sulfur has the characteristics of low price, abundant resources, and environmental friendliness, and has become a hot spot in the research and development of the next generation of high energy density lithium secondary batteries. However, lithium-sulfur batteries also face some serious problems: the conductivity of sulfur i...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01M4/36H01M4/38H01M4/62H01M10/0525
CPCH01M4/366H01M4/38H01M4/625H01M4/628H01M10/0525Y02E60/10
Inventor 孙克宁张婧岳昕阳王振华
Owner BEIJING INSTITUTE OF TECHNOLOGYGY
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