Nitrogen-doped carbon-coated graphite negative electrode material and preparation method thereof

A graphite negative electrode and coating technology, which is applied in the field of nitrogen-doped carbon-coated graphite negative electrode materials and its preparation, can solve the problem of first-time efficiency less than 360 specific capacity, affecting tap density, compaction density, and graphite sheet exfoliation cycle performance and other issues, to achieve the effect of being suitable for large-scale production, improving compaction density, excellent rate performance and cycle performance

Inactive Publication Date: 2015-01-14
FUJIAN XFH NEW ENERGY MATERIALS CO LTD
View PDF9 Cites 29 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, graphite-based materials still have some shortcomings as lithium-ion negative electrode materials, mainly in: weak interlayer interaction between graphite layers, poor compatibility with electrolyte, solvent molecules will be inserted into graphite layers during charging and discharging, resulting in graphite flakes Peeling of layers resulting in poor cycle performance
[0003] Chinese patent CN 103682350 B discloses a lithium battery negative electrode material coated with modified artificial graphite in pitch liquid phase. The modified artificial graphite negative electrode material has improved initia

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
  • Nitrogen-doped carbon-coated graphite negative electrode material and preparation method thereof
  • Nitrogen-doped carbon-coated graphite negative electrode material and preparation method thereof

Examples

Experimental program
Comparison scheme
Effect test

preparation example Construction

[0023] The preparation method of nitrogen-doped carbon coated graphite negative electrode material is described in detail as follows, including the following steps:

[0024] (1) Coating: Weigh graphite and ionic liquid, add them to a high-speed mixer, and disperse at a speed of 500-5000 r / min for 1-4 hours. After the treatment, graphite coated with ionic liquid is obtained; the ionic liquid is N-methylbutylpyrrolidine bistrifluoromethanesulfonimide salt, N-methylbutylpiperidine bistrifluoromethanesulfonimide salt, 1-ethyl-3-methylimidazole bistrifluoromethanesulfonimide Sulfonimide salt, 1-ethyl-3-methylimidazole tetrafluoroborate, trimethylpropylammonium bistrifluoromethanesulfonimide salt and 1-hexyl-3-methylimidazole bistrifluoromethane At least one of the sulfonimide salts, the purity of the ionic liquid is greater than or equal to 98%, and the molar ratio of nitrogen and carbon is 2:9 to 6:9.

[0025] Compared with the traditional solid-state carbon source precursors, io...

Embodiment 1

[0029] (1) Coating: Weigh 80 parts of graphite and 20 parts of ionic liquid, add them to a high-speed mixer, and disperse for 4 hours at a speed of 500r / min. After the treatment is completed, graphite coated with ionic liquid is obtained; the ionic liquid is N -Methylbutylpyrrolidine bistrifluoromethanesulfonimide salt, the purity of the ionic liquid is 98%, and the molar ratio of nitrogen and carbon is 2:9.

[0030] (2) Carbonization: The graphite coated with ionic liquid was placed in an atmosphere protection furnace for sintering, and the temperature was raised to 400 °C at a rate of 2 °C / min and kept for 8 hours to obtain a nitrogen-doped carbon-coated graphite negative electrode material. The nitrogen-doped carbon-coated graphite negative electrode material has a spherical shape, and the surface is uniformly covered with a layer of nitrogen-doped carbon material. The protective atmosphere used in the atmosphere protective furnace is selected from helium.

Embodiment 2

[0032] (1) Coating: 82 parts of graphite and 18 parts of ionic liquid were weighed, added to a high-speed mixer, and dispersed for 2 hours at a speed of 1000 r / min. After the treatment was completed, graphite coated with ionic liquid was obtained; the ionic liquid was N-methylbutylpiperidine bistrifluoromethanesulfonimide salt, the purity of the ionic liquid is 99%, and the molar ratio of nitrogen and carbon is 3:9.

[0033] (2) Carbonization: The graphite coated with ionic liquid was placed in an atmosphere protection furnace for sintering, and the temperature was raised to 800 °C at a rate of 8 °C / min and kept for 7 hours to obtain a nitrogen-doped carbon-coated graphite negative electrode material. The nitrogen-doped carbon-coated graphite negative electrode material has a spherical shape, and the surface is uniformly covered with a layer of nitrogen-doped carbon material. The protective atmosphere used in the atmosphere protective furnace is selected from nitrogen.

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

No PUM Login to view more

Abstract

The invention discloses a nitrogen-doped carbon-coated graphite negative electrode material and a preparation method thereof. The nitrogen-doped carbon-coated graphite negative electrode material is composed of the following raw materials in weight ratio: 80%-95% of graphite and 5%-20% of ionic liquid, wherein the outer surface of graphite is uniformly coated with the ionic liquid to form a core-shell type structure; the preparation method comprises the following steps: firstly coating, and then carbonizing. The graphite negative electrode material has relatively high compaction density, specific capacity and initial efficiency; the problem that an artificial graphite material is large in irreversible capacity loss and low in specific capacity when applied to real preparation of a lithium battery negative electrode is solved, and the rate capability and the circulating performance of a lithium ionic battery are greatly improved by doping with nitrogen; therefore, the material can be well applied to a power battery with high performance requirement. The preparation method disclosed by the invention is simple in process, convenient to operate and less in production equipment, thereby further reducing the cost; the method is convenient for popularization and application and suitable for large-scale production.

Description

technical field [0001] The invention relates to the technology in the field of battery electrode material preparation, in particular to a nitrogen-doped carbon-coated graphite negative electrode material and a preparation method thereof. Background technique [0002] With the deepening of the global energy crisis, the depletion of oil resources and the increasing harm of air pollution and global temperature rise, it is imperative to develop clean energy. In the development of new energy, lithium-ion batteries, which have the advantages of high working voltage, high energy density, stable discharge voltage, long cycle life and environmental friendliness, are widely used. Anode materials are one of the key factors to evaluate the overall performance of lithium-ion batteries. At present, the anode material of commercially used lithium batteries is mainly graphite, which has the characteristics of low lithium extraction / intercalation potential (0-0.25V vs Li / Li+), high capacity...

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): H01M4/36H01M4/583
CPCH01M4/366H01M10/0525Y02E60/10
Inventor 宋宏芳赵东辉戴涛周鹏伟
Owner FUJIAN XFH NEW ENERGY MATERIALS 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