Preparation method of graphene-polypyrrole-lithium titanate composite lithium battery negative electrode material

A battery negative electrode and graphene technology, applied in battery electrodes, secondary batteries, circuits, etc., can solve the problems of poor tightness of the coating layer on the surface of lithium titanate, high contact resistance, etc., to improve electrical conductivity and electrochemical performance , Energy saving and environmental protection technology, the effect of reducing contact resistance

Active Publication Date: 2016-08-17
HEFEI GUOXUAN HIGH TECH POWER ENERGY
View PDF4 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the coating layer on the lithium titanate surface of the material obtained by this preparation method is relatively poor, and the contact resistance between materials is relatively high.

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

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0020] Dissolve 20mL of pyrrole monomer in 200mL of absolute ethanol, add 2.5g of graphene to it, and disperse it ultrasonically at room temperature to obtain a uniform mixture a. Mix 80g of lithium titanate powder and sodium dodecylbenzenesulfonate Add 2.5g into solution a, obtain mixed solution b after ultrasonic dispersion, transfer solution b to ice-water bath and stir, keep the temperature at 0°C, then add 30g ferric chloride into solution b, keep stirring, and react for 3 hours Stop stirring. The reaction product was filtered and washed, placed in a vacuum drying oven, and baked at 100°C for 10 hours to obtain a graphene-polypyrrole-lithium titanate composite lithium battery negative electrode material.

Embodiment 2

[0022] Dissolve 20mL of pyrrole monomer in 200mL of deionized water, add 3.0g of graphene to it, and ultrasonically disperse at room temperature to obtain a uniform mixed solution a. Add 75g of lithium titanate powder and 1.5g of sodium p-toluenesulfonate to the solution In a, the mixed solution b was obtained after ultrasonic dispersion, and the solution b was stirred in an ice-water bath, and the temperature was kept at -2°C, and then 25g of hydrogen peroxide (27.5%) was added to the solution b, kept stirring, and stopped stirring after 5 hours of reaction . The reaction product was filtered and washed, placed in a vacuum drying oven, and baked at 80° C. for 20 hours to obtain a graphene-polypyrrole-lithium titanate composite lithium battery negative electrode material.

Embodiment 3

[0024] Dissolve 20mL of pyrrole monomer in 200mL of acetonitrile, then add 3.0g of graphene to it, and ultrasonically disperse at room temperature to obtain a uniform mixed solution a. Add 75g of lithium titanate powder and 1.5g of sodium benzenesulfonate to solution a , after ultrasonic dispersion, the mixed solution b was obtained, and the solution b was stirred in an ice-water bath, and the temperature was kept at 3°C, and then 20 g of ammonium persulfate was added to the solution b, kept stirring, and stopped stirring after 8 hours of reaction. The reaction product was filtered and washed, placed in a vacuum drying oven, and baked at 140° C. for 5 hours to obtain a negative electrode material for a graphene-polypyrrole-lithium titanate composite lithium battery.

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 preparation method of a graphene-polypyrrole-lithium titanate negative electrode material of a lithium battery and relates to the technical field of materials of lithium ion batteries. The preparation method comprises the following steps: firstly preparing a mixed liquid a of pyrrole monomers and graphene, then adding lithium titanate into the mixed liquid a, uniformly dispersing to obtain a mixed liquid b, then adding an initiating agent into the mixed liquid b to enable the pyrrole monomers to be polymerized into polypyrrole, filtering, cleaning and finally baking to obtain the graphene-polypyrrole-lithium titanate negative electrode material. According to the composite negative electrode material obtained by mixing the polypyrrole with the graphene and the lithium titanate, a graphene coating layer on the surface of the lithium titanate is relatively compact, so that the contact resistance among the materials can be greatly reduced and the conductivity and the electrochemical performance of the material are obviously improved; compared with a traditional carbon-coating method, for the method disclosed by the invention, the high-temperature calcining is not needed, the reducing atmosphere is not introduced, and the reduction of Ti<4+> in the lithium titanate is avoided, so that the rate performance and the safety performance of the battery are greatly improved, the energy-saving and environmental-friendly effects are achieved and the process is simple.

Description

technical field [0001] The invention relates to the technical field of lithium ion battery materials, in particular to a preparation method of a graphene-polypyrrole-lithium titanate composite lithium battery negative electrode material. Background technique [0002] At present, most commercial lithium-ion batteries use graphite and other carbon-based materials as negative electrodes, but graphite itself has defects such as irreversible capacity loss, poor safety performance, and poor cycle performance, which all affect the performance of lithium-ion batteries. Therefore, it is necessary to find a suitable Anode materials are one of the current research directions in the field of lithium-ion batteries. [0003] Lithium titanate negative electrode material has good electrochemical performance and safety performance, which is in line with the development direction of lithium ion power battery to high power and high rate, so it has a good application prospect. However, lithium...

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 & AuthorityPatents(China)
IPC IPC(8): H01M4/36H01M4/62
CPCH01M4/364H01M4/485H01M4/608H01M4/625H01M10/0525Y02E60/10
Inventor杨尘马元刘大军
OwnerHEFEI GUOXUAN HIGH TECH POWER ENERGY