Hydrothermal preparation method of graphene-coated sulfur/porous carbon composite positive electrode material

A composite cathode material, graphene coating technology, applied in battery electrodes, electrical components, electrochemical generators, etc., can solve problems such as low electrochemical performance, and achieve the effect of inhibiting dissolution loss

Active Publication Date: 2014-09-24
HARBIN INST OF TECH
View PDF2 Cites 31 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0007] The present invention aims to solve the technical problem of low electrochemical performance of existing graphene-coated sulfur-containing

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Hydrothermal preparation method of graphene-coated sulfur/porous carbon composite positive electrode material
  • Hydrothermal preparation method of graphene-coated sulfur/porous carbon composite positive electrode material
  • Hydrothermal preparation method of graphene-coated sulfur/porous carbon composite positive electrode material

Examples

Experimental program
Comparison scheme
Effect test

Example Embodiment

[0058] Specific embodiment 1: The hydrothermal preparation method of the graphene-coated sulfur / porous carbon composite cathode material of this embodiment is carried out in the following steps:

[0059] 1. Preparation of graphene slurry: the graphene slurry is composed of graphene and water, and graphene sheets are uniformly dispersed in the slurry; wherein the water content of the graphene slurry is 90%-99.99%;

[0060] 2. Preparation of sulfur / porous carbon composite material, where the porous carbon material is one or more of activated carbon, graphene, carbon black, carbon nanotubes, template porous carbon, carbon fiber, carbon aerogel, and carbide-derived carbon Composition, the mass ratio of sulfur to porous carbon in the sulfur / porous carbon composite material is 1:(0.02~20);

[0061] 3. According to the mass ratio of graphene in the graphene slurry to sulfur in the sulfur / porous carbon composite material as (0.02-20):1, add the sulfur / porous carbon composite material prepare...

Example Embodiment

[0063] Embodiment 2: The difference between this embodiment and Embodiment 1 is that the specific preparation method of the graphene slurry in step 1 is as follows:

[0064] (1) Weigh graphite and reducing agent; the mass ratio of graphite to reducing agent is 1:(0.1~1000); the reducing agent is one or a combination of ascorbic acid, KOH, NaOH, LiOH and ammonia;

[0065] (2) Oxidizing the graphite weighed in step (1) into graphite oxide;

[0066] (3) The concentration of graphite oxide is 0.01mg mL -1 ~50mg mL -1 , Adding the graphite oxide obtained in step (2) to water, peeling and dispersing for 0.5-10h under ultrasonic conditions with a frequency of 20-100KHz, to obtain an aqueous graphene oxide dispersion;

[0067] (4) Add a reducing agent to the graphene oxide aqueous dispersion obtained in step (3) at a temperature of 4℃~100℃, and reduce for 0.2h~24h under ultrasonic conditions with a frequency of 20~100KHz to obtain Graphene aqueous dispersion;

[0068] (5) The graphene aqueous ...

Example Embodiment

[0071] Specific embodiment three: This embodiment is different from specific embodiment one or two in that the method of oxidizing graphite to graphite oxide in step (2) is as follows: add 120 mL of H with a mass percentage of 98% in a dry beaker 2 SO 4 , Then put the beaker in an ice water bath, add 5g graphite and 2.5g NaNO 3 , Stirring at a speed of 50-500 rpm, while gradually adding 15g powdered KMnO 4 , Continue the reaction for 2h under ice-water bath and stirring conditions; move the beaker into a constant temperature oil bath at 35±1℃ and continue the reaction for 2h; slowly add 360mL of distilled water under stirring conditions at a speed of 50~500 rpm, and control the temperature to be constant Continue the constant temperature reaction at 75°C for 1h; add 1000mL of distilled water at 40°C, add 50mL of hydrogen peroxide with a mass percentage of 30%, and then vacuum filter; wash the filter cake with 5% mass percentage of hydrochloric acid until No SO in the filtrate 4 2...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

PropertyMeasurementUnit
First discharge capacityaaaaaaaaaa
Discharge capacityaaaaaaaaaa
Discharge capacityaaaaaaaaaa
Login to view more

Abstract

The invention provides a hydrothermal preparation method of a graphene-coated sulfur/porous carbon composite material and relates to a preparation method of the graphene-coated sulfur/porous carbon composite material for a positive electrode material of a lithium-sulfur storage battery. The hydrothermal preparation method is used for solving the technical problem that the electrochemical property of the positive electrode material of an existing lithium-sulfur battery, namely a graphene-coated sulfur-containing composite material, is low. The hydrothermal preparation method comprises the steps of mixing and scattering the sulfur/porous carbon composite material with graphene slurry or oxidized graphene slurry, carrying out hydrothermal synthesis to prepare a hydrogel column, and drying to obtain the graphene-coated sulfur/porous carbon composite material. According to the graphene-coated sulfur/porous carbon composite material prepared by utilizing the hydrothermal preparation method, the outer surfaces of the graphene sheet layers are coated with sulfur/porous carbon composite material particles, a graphene conduction network is generated among the particles, and the obtained graphene-coated sulfur/porous carbon composite material is in a hierarchical core-shell structure; the positive electrode material has the high specific capacity, the long cycle life and the good rate capability; the composite positive electrode material can be used as a positive electrode material in a lithium secondary battery.

Description

technical field [0001] The invention belongs to the field of lithium secondary batteries, in particular to a method for preparing a graphene-coated sulfur / porous carbon composite material through a hydrothermal crosslinking process and its application in lithium-sulfur batteries. Background technique [0002] With the technological revolution in the field of new energy and the rapid development of intelligent and mobile electronic equipment, the research and development of batteries for electric vehicles, energy storage and electronic products has attracted widespread attention. Lithium-ion batteries currently occupying an absolute dominant position in the market cannot meet the requirements of high energy density due to the limited theoretical capacity of lithium-intercalated cathode materials. A new generation of lithium secondary battery cathode materials with high specific capacity, high rate performance, and high safety performance has become the battery industry. The k...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
IPC IPC(8): H01M4/36H01M4/38H01M4/62
CPCH01M4/38H01M4/625H01M4/628H01M10/0525Y02E60/10
Inventor 贾铮李振华韦华宇李程远
Owner HARBIN INST OF TECH
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap