A silicon-based negative electrode material with heterostructure, a preparation method thereof and a lithium ion battery are disclosed

A technology for lithium-ion batteries and negative electrode materials, applied in battery electrodes, secondary batteries, structural parts, etc., can solve problems such as unfavorable industrial production, increased internal resistance of batteries, poor battery cycle performance, etc., and achieve good cycle stability , Improve lithium storage performance and good rate performance

Active Publication Date: 2019-01-25
EVE ENERGY CO LTD
View PDF16 Cites 7 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] Although the silicon material has such great advantages, it has great defects in practical applications: (1) During the charging and discharging cycle of the silicon material, due to the large volume expansion (~300%), it is easy to cause the active material to break into powder; In addition, the expansion and contraction of silicon particles lead to the continuous rupture and formation of the surface SEI (Solid electrolyte interphase, solid electrolyte interface) film, which consumes the limited electrolyte and lithium in the positive electrode, causing the SEI film to thicken and the internal

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

Examples

Experimental program
Comparison scheme
Effect test

Example Embodiment

[0084] Example 1

[0085] In this embodiment, the heterostructure silicon-based negative electrode material is prepared according to the following method:

[0086] (1) Mix the carbon nanotubes with a mixed acid of sulfuric acid and hydrochloric acid (the mass ratio of sulfuric acid to hydrochloric acid is 1:1), and the solid-to-liquid ratio of the mass of carbon nanotubes to the volume of the mixed acid is 0.5g / L. Condense and reflux at 100℃ for 3h After centrifugal separation, the solid obtained was washed and vacuum dried at 65°C for 1 hour to obtain oxidized carbon nanotubes;

[0087] Wherein, the carbon nanotubes are multi-walled carbon nanotubes, the diameter of the carbon nanotubes is 5-15 nm, and the length of the carbon nanotubes is 10-20 μm;

[0088] (2) The carbon oxide nanotubes described in step (1) were ultrasonically dispersed in water for 1.2 hours, mixed with ethyl orthosilicate, heated in a water bath at 65°C for reaction, the reaction time was 8 hours, and then centr...

Example Embodiment

[0095] Example 2

[0096] In this embodiment, the heterostructure silicon-based negative electrode material is prepared according to the following method:

[0097] (1) Mix the carbon nanotubes with a mixed acid of nitric acid and hydrochloric acid (the mass ratio of nitric acid to hydrochloric acid is 2:1). The solid-to-liquid ratio between the mass of carbon nanotubes and the volume of the mixed acid is 0.17 g / L, and reflux at 80°C. After 1h, centrifugal separation, washing and vacuum drying of the obtained solid at 50°C, vacuum drying time is 1h, to obtain oxidized carbon nanotubes;

[0098] Wherein, the carbon nanotubes are multi-walled carbon nanotubes, the diameter of the carbon nanotubes is 10-15 nm, and the length of the carbon nanotubes is 5-10 μm;

[0099] (2) After the carbon oxide nanotubes described in step (1) are dispersed in water for 0.5 ultrasonically, they are mixed with diallylphenyldimethylsilane and heated in a water bath at 50°C for reaction. The reaction time is...

Example Embodiment

[0106] Example 3

[0107] In this embodiment, the heterostructure silicon-based negative electrode material is prepared according to the following method:

[0108] (1) Mix the carbon nanotubes with a mixed acid of nitric acid and phosphoric acid (the mass ratio of nitric acid to hydrochloric acid is 1:3), the solid-liquid ratio of the mass of carbon nanotubes to the volume of the mixed acid is 1g / L, and reflux at 130°C for 5h , After centrifugal separation, washing and vacuum drying of the obtained solid at 80°C, the vacuum drying time is 1h, to obtain oxidized carbon nanotubes;

[0109] Wherein, the carbon nanotubes are multi-walled carbon nanotubes, the diameter of the carbon nanotubes is 15-20 nm, and the length of the carbon nanotubes is 20-30 μm;

[0110] (2) After the carbon oxide nanotubes described in step (1) are ultrasonically dispersed in water for 2 hours, they are mixed with triethoxysilane and heated in a water bath at 80°C for reaction. The reaction time is 10 hours. Th...

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
Diameteraaaaaaaaaa
Lengthaaaaaaaaaa
Particle sizeaaaaaaaaaa
Login to view more

Abstract

The invention provides a heterostructure silicon-based negative electrode material, a preparation method thereof and a lithium ion battery. The negative electrode material comprises carbon nanotubes,silicon distributed on the surface of the carbon nanotubes, and graphene coated on the silicon. 1) mixing that carbon nanotube and the acid, condensing and reflux, and then solid-liquid separation toobtain the carbon oxide nanotube; 2) after that carbon oxide nanotube is dispersed in wat, mixing with an organosilicon source, heating and reacting, and then solid-liquid separation; 3) mixing the product and the magnesium powder, crushing the mixture in an inert atmosphere, heating the mixture in an inert atmosphere, and heat treating the mixture; 4) under vacuum or inert atmosphere, taking carbon source as raw material to produce graphene by chemical vapor deposition on that product of the step 5) pickling to obtain the negative electrode material. The negative electrode material provided by the invention has good cycle stability and rate performance.

Description

technical field [0001] The invention belongs to the technical field of energy storage, and relates to a negative electrode material, in particular to a silicon-based negative electrode material with a heterogeneous structure, a preparation method thereof, and a lithium ion battery. Background technique [0002] With the wide application of consumer electronics and new energy vehicles, high specific energy lithium-ion batteries have become one of the research hotspots of researchers, and the capacity of materials directly affects the specific energy of batteries. At present, the theoretical gram capacity of commercial graphite-based negative electrode materials is only 372mAh / g, and its capacity has been developed and utilized to the limit. In comparison, the theoretical gram capacity of silicon materials is as high as 4200mAh / g (Li 4.4 Si). In addition, silicon also has a slightly higher lithium intercalation platform than graphite (0.2Vvs.Li + / Li), higher safety performa...

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): H01M4/36H01M4/38H01M4/583H01M4/62H01M10/0525C01B32/182
CPCC01B32/182H01M4/362H01M4/366H01M4/386H01M4/583H01M4/625H01M10/0525Y02E60/10
Inventor 何锐何巍刘金成袁中直
Owner EVE ENERGY CO LTD
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