Looking for breakthrough ideas for innovation challenges? Try Patsnap Eureka!

Method for preparing double-layer pitch carbon-coated lithium iron phosphate cathode material

A technology of carbon-coated lithium iron phosphate and positive electrode materials, which is applied to battery electrodes, electrical components, electrochemical generators, etc., can solve the problems of limited improvement in electrochemical performance, and achieve optimal potential energy distribution and conductivity. High, high specific capacity effect

Active Publication Date: 2018-03-27
HEFEI GUOXUAN HIGH TECH POWER ENERGY
View PDF4 Cites 8 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the degree of improvement in the electrochemical performance of materials prepared from these precursor carbons is limited.

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 preparing double-layer pitch carbon-coated lithium iron phosphate cathode material
  • Method for preparing double-layer pitch carbon-coated lithium iron phosphate cathode material
  • Method for preparing double-layer pitch carbon-coated lithium iron phosphate cathode material

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0034] refer to figure 2 , a method for preparing a double-layer pitch carbon-coated lithium iron phosphate positive electrode material, comprising the steps of:

[0035] S1. Mix low softening point asphalt with a mixed solvent. The solvent is obtained by mixing water and ethanol at a volume ratio of 1:1; then add lithium acetate, iron phosphate and lithium dihydrogen phosphate in sequence, including lithium, iron and phosphorus The molar ratio of lithium iron phosphate is 1:1:1, the mass ratio of the theoretical synthesis amount of lithium iron phosphate to low softening point pitch is 1:0.002, then ball milled for 36 hours, dried at 95°C, and sintered at 400°C for 4 hours under the protection of xenon gas to obtain carbon Coated lithium iron phosphate calcined material;

[0036] S2. Mix carbon-coated lithium iron phosphate calcined material and high softening point pitch for 5 minutes at a mass ratio of 1:0.2, place in a rotary rotary kiln at a speed of 15 rpm, and place i...

Embodiment 2

[0038] A method for preparing a double-layer pitch carbon-coated lithium iron phosphate cathode material, comprising the steps of:

[0039] S1. Mix low softening point asphalt with a mixed solvent. The solvent is obtained by mixing water and glycerol at a volume ratio of 1:1; then add lithium oxide, ferric oxide and phosphoric acid in sequence, including lithium, iron and phosphorus The molar ratio of the elements is 1:1:1, the mass ratio of the theoretically synthesized amount of lithium iron phosphate to the low softening point pitch is 1:0.1, then ball milled for 8 hours, dried at 105°C, and sintered at 300°C for 10 hours under the protection of xenon gas to obtain Carbon-coated lithium iron phosphate calcined material;

[0040] S2. Mix carbon-coated lithium iron phosphate calcined material and high softening point pitch for 25 minutes at a mass ratio of 1:0.05, place in a rotary rotary kiln at a speed of 1 revolution / min, and place it in a neon gas atmosphere. Raise the t...

Embodiment 3

[0042] A method for preparing a double-layer pitch carbon-coated lithium iron phosphate cathode material, comprising the steps of:

[0043] S1. Add 4g of asphalt with low softening point (70-85°C) into the ceramic ball mill tank, use water / methanol (volume ratio: 1:1) as solvent, then add 9.37g of lithium carbonate, 45.6g of ferrous oxalate and 29.2g ammonium dihydrogen phosphate, the theoretical synthesis amount of lithium iron phosphate and the mass ratio of low softening point asphalt is 1:0.1; put the ball mill jar into a planetary ball mill for 24 hours, take it out and put it in a drying oven at 100°C for drying ; Then put it into a nitrogen-protected tube furnace and sinter at 400 ° C for 4 hours to obtain a carbon-coated lithium iron phosphate calcined product;

[0044] S2. Mix the above-mentioned carbon-coated lithium iron phosphate calcined product with high softening point (270-290°C) asphalt at a mass ratio of 1:0.2, mix in a high-speed mixer for 15 minutes, and 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
softening pointaaaaaaaaaa
softening pointaaaaaaaaaa
Login to View More

Abstract

The invention discloses a method for preparing a double-layer pitch carbon-coated lithium iron phosphate cathode material, which belongs to the technical field of preparation of a new energy material.The method takes low-softening point asphalt as a carbon source, the low-softening point asphalt and a lithium iron phosphate precursor material are subjected to ball milling, the materials are subjected to low-temperature roasting to obtain a carbon-coated lithium iron phosphate pre-burning object, the carbon-coated lithium iron phosphate pre-burning object and the high-softening point asphalt are subjected to high-speed mixing, through two steps of low-temperature softening and high-temperature carbonization, and finally the double-layer pitch carbon-coated lithium iron phosphate cathode material is obtained. The low-softening point asphalt used in the method can effectively prevent growth of lithium iron phosphate crystal grains, carbon coating is primarily realized, after mixing withthe high-softening point asphalt for sintering, a potential energy distribution state of the surface of lithium iron phosphate can be optimized, and high-speed transmission of lithium ions in a material can be increased. The lithium iron phosphate cathode material has the advantages of high electron and ion conductivity, and high specific capacity, and is very suitable for the cathode material ofa lithium ion power battery.

Description

technical field [0001] The invention relates to the technical field of lithium ion batteries, in particular to a preparation method of a double-layer pitch carbon-coated lithium iron phosphate cathode material. Background technique [0002] Lithium-ion batteries have attracted much attention due to their high specific energy and long cycle life, and have been widely used in portable electronic devices, computers and other fields. Lithium-ion batteries are mainly composed of four parts: positive electrode material, negative electrode material, diaphragm and electrolyte. Among them, the positive electrode material is one of the most critical technologies that restrict the performance and price of the battery. Therefore, the research on positive electrode materials has become the focus of attention. The most positive electrode materials are mainly lithium iron phosphate, lithium cobalt oxide, lithium manganese oxide, lithium-rich manganese base, etc. In 1997, Goodenough first ...

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): H01M4/36H01M4/58H01M4/583H01M10/0525
CPCH01M4/366H01M4/5825H01M4/583H01M10/0525Y02E60/10
Inventor 齐美洲廖云龙郭钰静
Owner HEFEI GUOXUAN HIGH TECH POWER ENERGY
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Patsnap Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Patsnap Eureka Blog
Learn More
PatSnap group products

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

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap|About US| Contact US: help@patsnap.com