Core-shell silicon carbon composite negative electrode material for high-capacity type lithium ion battery and preparation method therefor

A technology for lithium-ion batteries and negative electrode materials, applied in battery electrodes, nanotechnology for materials and surface science, secondary batteries, etc., can solve the problems of difficult formation of solid electrolyte interface, aggravation of silicon corrosion and capacity decay, and active material shedding and other problems, to achieve excellent cycle stability, improve cycle stability, and improve conductivity

Active Publication Date: 2016-04-13
TIANJIN NORMAL UNIVERSITY
View PDF5 Cites 31 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Benefits of technology

This patented technology describes making materials that are more stable than previously used due to their ability to absorb large amounts of Li during charging or discharges without losing its effectiveness over time. These composites include both active ingredients (Si), such as silane monomers, and graphene oxide flakes dispersed throughout another matrix made from polymer resin). They improve upon existing methods by providing better control over charge transfer processes through specific chemical reactions.

Problems solved by technology

This patents describes different ways how lithiated carbons can be modified into suitable cathodes that improve battery properties like higher capacities or longer lifetimes compared to current methods involving expensive raw materials. Silane compounds were developed specifically for use in modifying these types of chemicals called organosilanes, but they also cause damage to certain components within cells when charged up. To address this problem, there was proposed a method where silica particles could replace some of them while maintaining good conductivity.

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
  • Core-shell silicon carbon composite negative electrode material for high-capacity type lithium ion battery and preparation method therefor
  • Core-shell silicon carbon composite negative electrode material for high-capacity type lithium ion battery and preparation method therefor
  • Core-shell silicon carbon composite negative electrode material for high-capacity type lithium ion battery and preparation method therefor

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0025] A method for preparing a silicon-carbon negative electrode material for a high-capacity lithium-ion battery, comprising the following steps:

[0026] (1) Add 0.5g of silicon nanoparticles and 0.05g of polyvinylpyrrolidone into 100mL of deionized water, ultrasonically disperse for 30min until the particles are evenly dispersed, and set aside.

[0027] (2) Take 40mL of the above solution and add 0.2g of glucose. After dissolving, transfer the solution to a reaction kettle with a polytetrafluoroethylene lining and seal it. Keep it warm at 180°C for 12h in a muffle furnace, and cool down to room temperature naturally. The solid product was centrifuged, washed, and vacuum-dried to obtain a silicon / amorphous carbon composite.

[0028] (3) The solid product obtained in step (2) was placed in a tube furnace under an Ar inert atmosphere, and was heated to 1000°C for carbonization for 1 hour to obtain the silicon-carbon composite negative electrode material of Example 1.

Embodiment 2

[0030] (1) Add 0.2g of silicon nanoparticles and 0.1g of polyvinylpyrrolidone into 40mL of deionized water, ultrasonically disperse for 5min until the particles are evenly dispersed, and set aside.

[0031] (2) Add 0.4g of citric acid to the above solution. After dissolving, transfer the solution to a reaction kettle with a polytetrafluoroethylene lining and seal it. Keep it in a muffle furnace at 220°C for 8 hours, and cool it down to room temperature naturally. The solid product was centrifuged, washed, and vacuum-dried to obtain a silicon / amorphous carbon composite.

[0032] (3) Place the solid product obtained in step (2) in a tube furnace, N 2 Under an inert atmosphere, the temperature was raised to 800° C. for carbonization for 5 hours to obtain the silicon-carbon composite negative electrode material of Example 2.

Embodiment 3

[0034] (1) Add 0.5g of silicon nanoparticles and 0.025g of cetyltrimethylammonium bromide into 50mL of deionized water, ultrasonically disperse for 60min until the particles are evenly dispersed, and set aside.

[0035] (2) Add 0.15g of starch and 0.1g of sucrose to the above solution. After dissolving, transfer the solution to a reaction kettle with a polytetrafluoroethylene lining and seal it. Keep it in a muffle furnace at 150°C for 24h, and cool it down to room temperature naturally. . The solid product was centrifuged, washed and dried in vacuo.

[0036] (3) The solid product obtained in step (2) was placed in a tube furnace, and under an Ar inert atmosphere, the temperature was raised to 900°C for carbonization for 2 hours, and the silicon-carbon composite negative electrode material of Example 3 was obtained.

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
Particle sizeaaaaaaaaaa
The average particle sizeaaaaaaaaaa
Thicknessaaaaaaaaaa
Login to view more

Abstract

The invention relates to a core-shell silicon carbon composite negative electrode material for a high-capacity type lithium ion battery and a preparation method therefor. The composite material is prepared from silicon nanoparticles and a low-crystallinity carbon material, wherein the silicon nanoparticles are taken as the core, and are coated with a low-crystallinity carbon layer formed by an organic carbon source to form a tightly-combined core-shell coating structure. According to the core-shell silicon carbon composite negative electrode material, the agglomeration among the silicon nanoparticles is effectively avoided; single silicon particles can be coated with amorphous carbon, and then the coated single silicon particles are subjected to high temperature carbonization, so that the degree of order of the carbon shell layer can be improved; the silicon volume expansion can be effectively retrained, the conductivity of the material can be improved, and the cycling performance and the rate capability of the material are further improved.

Description

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

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
Owner TIANJIN NORMAL UNIVERSITY
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