Unlock instant, AI-driven research and patent intelligence for your innovation.

Graphene-and-carbon-coated lithium iron phosphate lithium ion battery positive electrode material and production method thereof

A technology for lithium iron phosphate and lithium ion batteries, which is applied in battery electrodes, circuits, electrical components, etc., can solve problems such as chemical properties that have not been publicly reported, and achieve improved electrochemical kinetics, electrode activity, and material electrochemistry. Excellent performance and the effect of improving point contact

Inactive Publication Date: 2015-08-26
TIANJIN UNIV
View PDF8 Cites 9 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0007] According to the literature search, the present invention uses graphene and carbon co-coating for lithium ferrous phosphate to carry out composite modification, and the low-temperature electrochemical performance has not been publicly reported.

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
  • Graphene-and-carbon-coated lithium iron phosphate lithium ion battery positive electrode material and production method thereof
  • Graphene-and-carbon-coated lithium iron phosphate lithium ion battery positive electrode material and production method thereof
  • Graphene-and-carbon-coated lithium iron phosphate lithium ion battery positive electrode material and production method thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0032] Weigh 2.97 g of carbon-coated lithium iron phosphate powder and disperse it into 120 ml of absolute ethanol to form a suspension, and weigh 0.03 g of graphene powder and disperse it into 30 ml of absolute ethanol to form a suspension. Suspend the two separately The liquid was ultrasonically shaken for 20 minutes, and then stirred at room temperature for 4 hours. Then add the graphene suspension dropwise to LiFePO 4 In the / C suspension, continue to stir at room temperature for 3 hours, and then stir under heating at 60°C until the absolute ethanol evaporates to obtain a paste. The obtained paste was put in an oven, dried at 80°C for 12 hours, and then ground through a 280 mesh sieve to obtain a black powder. Place the sieved black powder in a tube furnace in a nitrogen-hydrogen mixed atmosphere (VN 2 :VH 2 =95:5) Heat treatment at 400°C for 2 hours, grind through a 325-mesh sieve again, and finally obtain a lithium ion battery cathode material with a mass fraction of 1% ...

Embodiment 2

[0035] Weigh 2.91 g of carbon-coated lithium iron phosphate powder and disperse into 120 ml of absolute ethanol to form a suspension, weigh 0.09 g of graphene powder and disperse into 30 ml of absolute ethanol to form a suspension, respectively suspend the two The liquid was ultrasonically shaken for 20 minutes, and then stirred at room temperature for 4 hours. Then add the graphene suspension dropwise to LiFePO 4 In the / C suspension, continue to stir at room temperature for 3 hours, and then stir under heating at 60°C until the absolute ethanol evaporates to obtain a paste. The obtained paste was put in an oven, dried at 80°C for 12 hours, and then ground through a 280 mesh sieve to obtain a black powder. Place the sieved black powder in a tube furnace in a nitrogen-hydrogen mixed atmosphere (VN 2 :VH 2 =95:5) Heat treatment at 400°C for 2 hours, grind through a 325-mesh sieve again, and finally obtain a lithium ion battery cathode material with a mass fraction of 3% graphene...

Embodiment 3

[0039] Weigh 2.85 g of carbon-coated lithium iron phosphate powder and disperse it into 120 ml of absolute ethanol to form a suspension, and weigh 0.15 g of graphene powder and disperse into 30 ml of absolute ethanol to form a suspension. Suspend the two separately The liquid was ultrasonically shaken for 20 minutes, and then stirred at room temperature for 4 hours. Then add the graphene suspension dropwise to LiFePO 4 In the / C suspension, continue to stir at room temperature for 3 hours, and then stir under heating at 60°C until the absolute ethanol evaporates to obtain a paste. The obtained paste was put in an oven, dried at 80°C for 12 hours, and then ground through a 280 mesh sieve to obtain a black powder. Place the sieved black powder in a tube furnace in a nitrogen-hydrogen mixed atmosphere (VN 2 :VH 2 =95:5) Heat treatment at 400°C for 2 hours, grind through a 325 mesh sieve again, and finally obtain a lithium ion battery cathode material with a mass fraction of 5% gra...

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 graphene-and-carbon-coated lithium iron phosphate lithium ion battery positive electrode material and a production method thereof. The graphene-and-carbon-coated lithium iron phosphate lithium ion battery positive electrode material is made of grapheme-and-carbon-coated lithium iron phosphate, wherein the mass percent of graphene is 1%-9%. The graphene-and-carbon-coated lithium iron phosphate is prepared from a suspension mixing method to overcome the deficiency of poor low-temperature electrochemical performance of existing carbon-coated lithium iron phosphate positive electrode materials. The lithium ion battery positive electrode material with good low-temperature electrochemical performance is produced through the modification method being simple in process and low in cost. A button cell assembled with the positive electrode material has the capacity retention rate of 95.1% after the circulation of 100 times at 1C rate at the temperature of 0 DEG C and the capacity retention rate of 90.1% after the circulation of 100 times at 1C rate at the temperature of -20 DEG C.

Description

Technical field [0001] The invention belongs to the technical field of lithium ion battery cathode materials, and particularly relates to a graphene and carbon (C) composite modified lithium iron phosphate (LiFePO 4 ) Li-ion battery cathode material and preparation method thereof. Background technique [0002] Lithium-ion batteries have excellent characteristics such as high specific energy, good cycle performance, and no pollution to the environment. The application range has been expanded from daily life to electric vehicles, military and aerospace fields. Therefore, lithium-ion batteries must meet the requirements for use in low-temperature environments, and the current low-temperature charge and discharge performance of lithium-ion batteries cannot meet the demand. Therefore, it is valuable to study and improve its low-temperature performance. [0003] Among the many lithium phosphate cathode materials composed of transition metals, lithium iron phosphate has many advantages as...

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
CPCY02E60/10
Inventor 郭瑞松
Owner TIANJIN UNIV