Lithium sulfur battery positive electrode material and preparation method thereof

A lithium-sulfur battery, cathode material technology, applied in battery electrodes, circuits, electrical components, etc., can solve the problems of low utilization rate of active materials, low cycle life, low safety performance, etc., achieve excellent electrical conductivity and mechanical properties, guarantee utilization, improve the effect of adsorption

Active Publication Date: 2017-05-31
SHENZHEN GRADUATE SCHOOL TSINGHUA UNIV
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0007] At present, lithium-sulfur batteries have problems such as low utilization of active materials, low cycle life, poor rate performance and low safety performance, which seriously hinder their application.

Method used

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  • Lithium sulfur battery positive electrode material and preparation method thereof
  • Lithium sulfur battery positive electrode material and preparation method thereof

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preparation example Construction

[0038] In one embodiment, a preparation method for preparing the positive electrode material of the lithium-sulfur battery comprises the following steps:

[0039] S1. Preparation of TiO 2 Uniform mixture of nanoparticles, PVA, carbon nanotubes;

[0040] S2. Using the homogeneous mixed solution, under the water-in-oil emulsion system, prepare a solution containing carbon nanotube microspheres by a water-in-oil method;

[0041] S3. After removing the moisture in the system by heating in a water bath, vacuum drying to obtain a solid powder material of spherical structure particles;

[0042] S4. Carbonize the obtained solid powder material to cause cyclization, oxidation, and crosslinking reactions of PVA molecules to form ladder molecules and aromatization structures, and then obtain interconnected nanostructures formed by intertwining carbon nanotubes. Micron-sized carbon spheres with microporous structure, TiO 2 Nanoparticles are evenly dispersed and embedded in the micron-s...

Embodiment 1

[0051] Step 1: Prepare a uniform mixture of PVA and CNTs. Weigh 0.2g of PVA powder, add it to a certain amount of deionized water, heat and stir at 80°C until completely dissolved, add 0.1g of carbon nanotubes into the system, and weigh 10wt% nano-TiO 2 The nanoparticles were added to the above solution, and the stirring was continued for 2 h to obtain a uniform mixed solution. Among them, the molecular weight M of PVA w for 10,000.

[0052] The second step: preparing carbon nanotube microspheres by the water-in-oil method. Put the n-dodecane solution under the high-speed dispersing homogenizer, and add Span 80 as an emulsifier under the effect of the rotating speed of 12000 rpm, and slowly add the homogeneous solution prepared in the first step to the normal solution after 1 minute of reaction. In the dodecane solution, continue to act for 1 min under the high-speed dispersing homogenizer.

[0053] Step 3: Stir the obtained solution at 90° C. for 2 hours to completely eva...

Embodiment 2

[0057] Step 1: Prepare a uniform mixture of PVA and CNTs. Weigh 0.2g of PVA powder, add it to a certain amount of deionized water, heat and stir at 80°C until it is completely dissolved, add 0.1g of carbon nanotubes into the system, and weigh nano-TiO with a mass fraction of 20wt%. 2 The nanoparticles were added to the above solution, and the stirring was continued for 2 h to obtain a uniform mixed solution. Among them, the molecular weight M of PVA w for 10,000.

[0058] The second step: preparing carbon nanotube microspheres by the water-in-oil method. Put the n-dodecane solution under the high-speed dispersing homogenizer, and add Span 80 as an emulsifier under the effect of the rotating speed of 12000 rpm, and slowly add the homogeneous solution prepared in the first step to the normal solution after 1 minute of reaction. In the dodecane solution, continue to act for 1 min under the high-speed dispersing homogenizer.

[0059] Step 3: Stir the obtained solution at 90° C...

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Abstract

The invention discloses a lithium sulfur battery positive electrode material and a preparation method thereof, wherein the lithium sulfur battery positive electrode material includes a sulfur carbon nano composite material, the sulfur carbon nano composite material includes carbon nanotubes, TiO2 nano particles and nano sulfur powder, the carbon nanotubes are intertwined to form micron grade carbon balls with nano micropore structures which are interconnected, the TiO2 nanoparticles areuniformly dispersed and embedded in the micron grade carbon balls to form composite carbon microspheres, and the nano sulfur powder is evenly filled in the composite carbon microspheres. Sulfur is infiltrated into the composite microspheres which are formed by coating of the TiO2 nanoparticles with the carbon nanotubes, and the lithium sulfur battery positive electrode material is prepared in a water-in-oil microemulsion system. The obtained material is a regular spherical structure with monodispersity and uniformity. After sulfur infiltration, the sulfur is uniformly filled into the microspheres, and the capacity is fully utilized during charging and discharging processes, and the structure can be controlled at the same time.

Description

technical field [0001] The invention relates to a lithium-sulfur battery cathode material and a preparation method thereof. Background technique [0002] New energy storage devices represented by lithium-ion batteries and supercapacitors have received great attention. Lithium-ion batteries have the advantages of large specific capacity, high energy density, and environmental protection. They are the preferred energy storage devices for mobile electronic products such as mobile phones and tablets. LiMn is currently widely used in the positive electrode of lithium-ion batteries 2 o 4 、LiCoO 2 、LiFePO 4 The theoretical specific capacity of traditional materials such as conventional materials is below 300mAh / g, which cannot meet the cruising range requirements of new energy vehicles. The Li-S battery system can provide a theoretical specific capacity as high as 1675mAh / g, and it is expected to develop into a new type of energy storage system in the short term. However, the...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01M4/58H01M4/38
CPCH01M4/38H01M4/382H01M4/581Y02E60/10
Inventor 夏悦李宝华贺艳兵禇晓东
Owner SHENZHEN GRADUATE SCHOOL TSINGHUA UNIV
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