Lithium iron phosphate anode materials of three-dimensional conductive network structure and preparation method thereof

A technology of lithium iron phosphate and network structure, which is applied in the field of lithium iron phosphate cathode material and its preparation, can solve the problems such as the reduction of specific capacity and tap density, and the inability to form an effective continuous conductive network.

Active Publication Date: 2015-07-15
德阳威旭锂电科技有限责任公司
View PDF3 Cites 12 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Because, if the amount of coating is too small, an effective continuous conductive network cannot be formed between LFP molecules; if the amount of coating is too large, the specific capacity and tap density will also be reduced.

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
  • Lithium iron phosphate anode materials of three-dimensional conductive network structure and preparation method thereof
  • Lithium iron phosphate anode materials of three-dimensional conductive network structure and preparation method thereof
  • Lithium iron phosphate anode materials of three-dimensional conductive network structure and preparation method thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0035] Weigh 3.36 g LiOH·H 2 O was dissolved in 2000 mL deionized water, and a 0.04 M LiOH solution was prepared, and spectroscopically pure graphite plates were used as the cathode and anode, respectively, and the current density was 25 mA cm -1 , electrolyzed for 12 hours, and the precipitate obtained by electrolysis was centrifuged at 10,000 rpm and washed twice with water, and then dried at 100°C. The results of transmission electron microscopy observations are as follows: figure 2 As shown: the obtained ECGO has a nearly spherical structure; the results of infrared spectroscopy and nuclear magnetic resonance detection show that the obtained ECGO has a certain degree of oxidation, and the surface has a large number of oxygen-containing functional groups such as hydroxyl, aldehyde and carboxyl groups. The oxygen content of the ECGO obtained by the electrochemical oxidation is less than 10%, and its resistivity measured by four probes is 4 Ω cm, which has good conductivity...

Embodiment 2

[0040] Weigh 1.68 g LiOH·H 2 O was dissolved in 2000 mL deionized water, and a 0.02 M LiOH solution was prepared, and spectrally pure graphite plates were used as the cathode and anode, respectively, with a current density of 30 mA cm -1 , electrolyzed for 24 hours, and the precipitate obtained by electrolysis was centrifuged at 10,000 rpm and washed twice with water, and then dried at 100°C. Similar to Example 1, transmission electron microscope observation shows that the obtained ECGO has a nearly spherical structure; infrared spectrum and nuclear magnetic resonance detection results show that the obtained ECGO has a certain degree of oxidation, and the surface has a large number of oxygen-containing functional groups such as hydroxyl, aldehyde and carboxyl groups. The oxygen content of the ECGO obtained by the electrochemical oxidation is less than 10%, and its resistivity measured by four probes is 6 Ω cm, which has good conductivity and hydrophilicity.

[0041] Measure 1...

Embodiment 3

[0045] Weigh 0.84 g LiOH·H 2 O was dissolved in 2000 mL deionized water, and a 0.01 M LiOH solution was prepared, and spectroscopically pure graphite plates were used as the cathode and anode respectively, and the current density was 35 mA cm -1 , electrolyzed for 36 hours, the precipitate obtained by electrolysis was centrifuged at 10000 rpm and washed twice with water, and the precipitate obtained was dried at 100 °C. Similar to Example 1, transmission electron microscope observation shows that the obtained ECGO has a nearly spherical structure; infrared spectrum and nuclear magnetic resonance detection results show that the obtained ECGO has a certain degree of oxidation, and the surface has a large number of oxygen-containing functional groups such as hydroxyl, aldehyde and carboxyl groups. The oxygen content of the ECGO obtained by the electrochemical oxidation is less than 10%, and its resistivity measured by four probes is 8 Ω cm, which has good conductivity and hydroph...

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
sizeaaaaaaaaaa
sizeaaaaaaaaaa
Login to view more

Abstract

The invention discloses lithium iron phosphate anode materials of a three-dimensional conductive network structure and a preparation method thereof and belongs to the technical field of lithium ion battery anode materials. The materials are compound materials composed of lithium iron phosphate (LFP), electrochemical stripping graphite oxide (ECGO) and a carbon covering film, and the materials are of the three-dimensional structure that the outer layer is covered with the carbon film and the ECGO is connected with the LFP molecules internally. The preparation method comprises the steps that graphite block materials are stripped by the electrochemical oxidation technology, and the ECGO which is good in hydrophilia and electrical conductivity is obtained; the LFP (LFP/ECGO) with the surface combined with a large amount of ECGO is prepared by the hydrothermal method; a layer of carbon film is formed on the surface of the LFP/ECGO by the pressure burning technology. The electrical conductivity performance of the materials can be improved, and the specific capacity and tap density of the materials are not affected much. According to the obtained LFP anode materials (LFP/ECGO) of the 3D conductive network structure, compared with the pure LFP, LFP/ECGO or LFP/C, the electrochemical performance of the LFP/ECGO/C materials is the best.

Description

technical field [0001] The invention belongs to the technical field of cathode materials for lithium ion batteries, and in particular relates to a lithium iron phosphate cathode material with a three-dimensional conductive network structure and a preparation method thereof. technical background [0002] Lithium iron phosphate (LFP, the molecular formula is LiFePO 4 ) has been proved to have a high theoretical capacity (170 mAh g -1 ), good cycle performance (can be recycled more than 2000 times), moderate working potential (3.4 V vs. Li + / Li), environmental friendliness, high safety, and low price, it is one of the ideal cathode materials for a new generation of lithium-ion batteries. However, its disadvantages of poor electronic conductivity and slow lithium ion migration rate affect its rate performance and severely limit its application in the battery industry. People try to solve the above problems by reducing the particle size to shorten the transmission distance ...

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): H01M4/58H01M4/583H01M4/133H01M4/136H01M4/1393H01M4/1397
CPCH01M4/136H01M4/1397H01M4/362H01M4/5825H01M2004/028Y02E60/10
Inventor 张永志肖丹郭勇王强黄建新王隽李玲琛
Owner 德阳威旭锂电科技有限责任公司
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