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A kind of lithium-sulfur battery positive electrode material and its preparation method and lithium-sulfur battery

A technology for lithium-sulfur batteries and positive electrode materials, applied in battery electrodes, lithium batteries, positive electrodes, etc., can solve the problems of poor sulfur conductivity, reduced cycle stability, and reduced ionic conductivity, so as to make up for the shortcomings of sulfur insulation, Improve cycle stability and ease volume expansion

Active Publication Date: 2020-07-21
WUHAN UNIV OF SCI & TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, lithium-sulfur batteries also have their own unique problems: (1) The conductivity of sulfur is very poor, and the final product of the reaction, Li 2 S 2 and Li 2 S is an insulator, which leads to poor battery rate performance; (2) polysulfides, the intermediate products of lithium-sulfur batteries, will dissolve into the electrolyte, reducing the ion conductivity, and the movement of polysulfides between the positive and negative electrodes makes The active material is lost, thereby reducing the cycle stability; (3) During the charge and discharge process, the volume of sulfur will increase, which is easy to damage the battery and bring safety hazards
However, the above methods have limited effects on the improvement of material conductivity and the inhibition of polysulfide shuttle effect, and the ability to simultaneously improve the rate performance and cycle performance of lithium-sulfur batteries is also limited.

Method used

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  • A kind of lithium-sulfur battery positive electrode material and its preparation method and lithium-sulfur battery
  • A kind of lithium-sulfur battery positive electrode material and its preparation method and lithium-sulfur battery
  • A kind of lithium-sulfur battery positive electrode material and its preparation method and lithium-sulfur battery

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preparation example Construction

[0035] The present invention provides a preparation method for the lithium-sulfur battery cathode material described in the above technical solution, comprising the following steps:

[0036] 1) adding cyclohexamethylenetetramine, cobalt chloride hexahydrate, and ammonium metavanadate precursors into pure water and mixing to obtain a mixture;

[0037] (2) the mixture prepared by step (1) is put into a water bath, and stirred to obtain the cobalt vanadate powder material;

[0038] (3) Put the cobalt vanadate material described in the step (2) in a tube furnace, and conduct heat treatment in a carbon monoxide atmosphere to carry out phase separation and synchronous growth of a carbon nanotube coating layer.

[0039] (4) The composite material described in step (3) is mixed with sublimed sulfur and then subjected to vacuum low-temperature heat treatment to obtain the lithium-sulfur battery positive electrode material.

[0040] The preparation principle of the lithium-sulfur battery...

Embodiment 1

[0051] This embodiment provides the preparation method of the positive electrode material of the lithium-sulfur battery, comprising the following steps:

[0052] (1) Mix cyclohexamethylenetetramine, cobalt chloride hexahydrate, and ammonium metavanadate precursor at 1:5:12.5 to obtain a mixture;

[0053] (2) Put the container containing the reactants into an 80°C water bath, and stir continuously for 4 hours to obtain the cobalt vanadate material;

[0054] (3) The cobalt vanadate obtained by the reaction is suction-filtered 2 times to remove the unreacted precursor;

[0055] (4) Put the final cobalt vanadate material in a tube furnace, heat-treat it in a carbon monoxide atmosphere, heat it up to 600°C at a heating rate of 5°C / min, and hold it for 2h for phase separation and simultaneous growth of carbon nanotubes Network coating layer, after the product is cooled to room temperature with the furnace, take it out.

[0056] (5) Mix the above-mentioned composite material with s...

Embodiment 2

[0059] This embodiment provides the preparation method of the positive electrode material of the lithium-sulfur battery, comprising the following steps:

[0060] (1) Mix cyclohexamethylenetetramine, cobalt chloride hexahydrate, and ammonium metavanadate precursor at 1:5:12.5 to obtain a mixture;

[0061] (2) Put the container containing the reactants into an 80°C water bath, and stir continuously for 4 hours to obtain the cobalt vanadate material;

[0062] (3) The cobalt vanadate obtained by the reaction is suction-filtered 2 times to remove the unreacted precursor;

[0063] (4) Put the final cobalt vanadate material in a tube furnace, heat-treat it in a carbon monoxide atmosphere, heat it to 580°C at a heating rate of 5°C / min, and hold it for 3h for phase separation and simultaneous growth of carbon nanotubes The cladding layer is taken out after the product is cooled to room temperature with the furnace.

[0064] (5) Mix the above-mentioned composite material with sublimed...

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Abstract

The invention discloses a lithium sulfur battery positive electrode material, a preparation method thereof and a lithium sulfur battery. The positive electrode material of the lithium sulfur battery comprises a plurality of vanadium oxide nanosheets, a plurality of cobalt particles dispersed on each vanadium oxide nanosheet, carbon nanotubes grown on the surfaces of the plurality of cobalt particles, and sulfur monomers dispersed in the carbon nanotubes and in a network formed by the carbon nanotubes at the same time. The positive electrode material of the lithium-sulfur battery provided by the invention takes cobalt metal and transition metal oxide as templates to grow carbon nanotubes to carry sulfur, Cobalt and carbon nanotubes are good conductive materials, which make up for the shortcomings of sulfur insulation and greatly improve the rate performance and cycle stability of lithium sulfide batteries. Moreover, the preparation method is simple in process, convenient in operation, friendly in environment, favorable for large-scale production, and has practicability.

Description

technical field [0001] The invention belongs to the field of lithium-sulfur battery cathode materials, and more specifically relates to a lithium-sulfur battery cathode material, a preparation method thereof, and a lithium-sulfur battery. Background technique [0002] With the development of modern industry and the popularization of automobiles, fossil energy is decreasing day by day, environmental problems are becoming more and more serious, and the situation is not optimistic. There is an urgent need to study clean and renewable energy to replace the existing non-renewable fossil energy. At the same time, the solution to the energy storage problem is put on the agenda. At present, the research and application of lithium-ion batteries are relatively extensive. Because of their high power density, relatively high energy density, long cycle life, and environmental protection, they are widely used in various mobile power sources, large-scale energy storage equipment and new en...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H01M4/36H01M4/38H01M4/62H01M10/052
CPCH01M4/366H01M4/38H01M4/625H01M4/626H01M4/628H01M10/052H01M2004/021H01M2004/028Y02E60/10
Inventor 付继江秦萍高标张旭明霍开富黄超
Owner WUHAN UNIV OF SCI & TECH