Method for performing microwave solvothermal in-situ synthesis on carbon-coated lithium iron phosphate

A carbon-coated lithium iron phosphate and microwave solvothermal technology, which is applied in electrical components, battery electrodes, circuits, etc., can solve the problems of easy agglomeration of lithium iron phosphate powder, difficulty in obtaining uniform size, and long reaction period, so as to improve the Electrochemical performance, ensuring uniformity, the effect of short reaction cycle

Inactive Publication Date: 2015-07-01
WUHAN UNIV OF TECH
View PDF2 Cites 8 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

High-temperature solid-phase synthesis method is the most common method used in industrial production, but this method needs to be carried out at high temperature, the equipment investment is large, the energy consumption is high, and it is not environmentally friendly. Moreover, the prepared lithium iron phosphate powder is easy to agglomerate and difficult to obtain. Lithium iron phosphate powder with uniform size and regular shape
However, although the size and shape of the powder are easy to control and the phase is uniform in the hydrothermal synthesis of lithium iron phosphate, the reaction cycle is long and usually takes more than ten hours to complete.

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
  • Method for performing microwave solvothermal in-situ synthesis on carbon-coated lithium iron phosphate
  • Method for performing microwave solvothermal in-situ synthesis on carbon-coated lithium iron phosphate
  • Method for performing microwave solvothermal in-situ synthesis on carbon-coated lithium iron phosphate

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0039] 0.01mol LiAc·2H 2 O and 0.01mol Fe(NO 3 ) 3 ·9H 2 O is dispersed in 70mL diethylene glycol, after stirring evenly, slowly add 0.01mol H 3 PO 4 , And constantly stirring, then add 3mL ethylenediamine dropwise, stir evenly to obtain the precursor solution. Take 40 mL of the precursor solution into a 100 mL microwave reactor, and react at 220° C. for 1 h. After cooling to room temperature, the reaction solution is washed with deionized water and ethanol several times and then dried in an oven at 100° C. to obtain the precursor. Put the precursor in a reducing atmosphere (5vol.%H 2 And 95vol.% Ar) was heated to 700°C and calcined for 10 hours. After the furnace is naturally cooled to room temperature, the carbon-coated three-dimensional bi-continuous structure LiFePO is obtained 4 / C.

[0040] The carbon-coated lithium iron phosphate prepared by the above method is subjected to powder X-ray diffraction, and its spectrum is as follows figure 1 Shown. by figure 1 It can be seen...

Embodiment 2

[0042] Add 0.005mol LiAc·2H 2 O and 0.005mol Fe(NO 3 ) 3 ·9H 2 Disperse O in 70mL diethylene glycol, stir evenly, slowly add 0.005mol H 3 PO 4 , And keep stirring, then add 3mL ethylenediamine dropwise, stir evenly to obtain the precursor liquid. Take 35mL of the precursor solution into a 100mL microwave reactor and react at 220°C for 1 hour. After cooling to room temperature, the reaction solution is washed with deionized water and ethanol for several times and then dried in an oven at 100°C to obtain the precursor. Put the precursor in a reducing atmosphere (5vol.%H 2 And 95vol.% Ar) was heated to 700°C and calcined for 10 hours. After the furnace is naturally cooled to room temperature, a carbon-coated three-dimensional bi-continuous structure LiFePO is obtained 4 / C.

[0043] The scanning electron micrograph (SEM) of the prepared precursor (a) and the calcined product lithium iron phosphate (b) are as follows Figure 4 Shown. by Figure 4 (a) It can be seen that the precurso...

Embodiment 3

[0045] Add 0.005mol LiAc·2H 2 O and 0.005mol Fe(NO 3 ) 3 ·9H 2 O is dispersed in 70mL diethylene glycol, after stirring evenly, slowly add 0.005mol H 3 PO 4 , And keep stirring, then add 3mL ethylenediamine dropwise, stir evenly to obtain the precursor liquid. Take 50 mL of the precursor solution into a 100 mL microwave reactor, and react at 220° C. for 20 min. After cooling to room temperature, the reaction solution was washed with deionized water and ethanol several times and then dried in an oven at 100° C. to obtain the precursor. Put the precursor in a reducing atmosphere (5vol.%H 2 And 95vol.% Ar) was heated to 700°C and calcined for 10 hours. After the furnace is naturally cooled to room temperature, a carbon-coated three-dimensional bi-continuous structure LiFePO is obtained 4 / C.

[0046] The scanning electron micrograph (SEM) of the prepared precursor is shown as Figure 5 Shown. It can be seen from the figure that the precursor is a bi-continuous structure formed by i...

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
sizeaaaaaaaaaa
thicknessaaaaaaaaaa
sizeaaaaaaaaaa
Login to view more

Abstract

The invention relates to a method for performing microwave solvothermal in-situ synthesis on carbon-coated lithium iron phosphate. The method comprises the following steps: dispersing a lithium source and an iron source in an alcohol reducing agent; adding a phosphorus source, stirring, adding a chelating agent, and stirring, thereby obtaining a precursor solution; adding part of the precursor solution into a microwave reactor, heating and reacting to obtain a product; washing the obtained product and drying, thereby obtaining a precursor; and calcining the precursor in a reducing atmosphere, thereby obtaining the product. The method disclosed by the invention has the beneficial effects that the time can be saved by virtue of in-situ carbon coating, and the uniformity of coated carbon can be ensured. Meanwhile, the conductivity of the lithium iron phosphate can be enhanced by virtue of the coated carbon, and the electrochemical performance is improved; the lithium iron phosphate is of a three-dimensional bi-continuous structure, nano-particles in the structure are connected with one another, a three-dimensional network is formed, the lithium-ion transmission distance is greatly shortened, and the electrochemical performance of the material is improved; the reaction period is short, and the process is simple; and the prepared lithium iron phosphate is high in specific capacity, good in cycle performance, high in repeatability and excellent in processability.

Description

Technical field [0001] The invention belongs to the technical field of energy material manufacturing, and specifically relates to a method for microwave solvothermal in-situ synthesis of carbon-coated lithium iron phosphate. Background technique [0002] As a high-performance rechargeable green power source, lithium-ion batteries have been widely used in various portable electronic products and communication tools in recent years, and have been gradually developed as power sources for electric vehicles. In the research of lithium-ion batteries, the research and development of new electrode materials, especially cathode materials, is extremely critical. [0003] Among the currently widely studied cathode materials for lithium-ion batteries, LiFePO 4 It has the advantages of low price, good safety performance and thermal stability, no pollution, and high mass ratio energy. It is a kind of lithium ion battery cathode material with great potential. However, the low electronic conducti...

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
Patent Type & Authority Applications(China)
IPC IPC(8): H01M4/58H01M4/136
CPCH01M4/136H01M4/5825H01M4/625Y02E60/10
Inventor 李昱张倩许骏蒙黄绍专王洪恩陈丽华苏宝连
Owner WUHAN UNIV 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