A kind of preparation method of lithium titanate-graphene composite negative electrode material

A graphene composite, negative electrode material technology, applied in nanotechnology, battery electrodes, nanotechnology and other directions for materials and surface science, can solve the problem of uneven surface coating of lithium titanate, poor surface coating tightness, Insufficient density of the coating layer, etc., to achieve the effect of being conducive to high-rate discharge, increasing conductivity, and improving high-rate performance

Inactive Publication Date: 2020-09-01
MCNAIR TECH +3
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

However, the composite materials obtained by this method still have problems such as poor compactness of the surface coating layer, high contact resistance between materials, and uneven coating.
In addition, in the preparation method disclosed in Chinese patent CN201610218313.3, a two-component chelating agent method is used to prepare lithium titanate-graphene composite materials, although it can improve the coating layer compactness on the surface of lithium titanate to a certain extent; however, Because the method adds a two-component chelating agent, on the one hand, this greatly shortens the reaction time between the particles during the preparation process, and accelerates the agglomeration between the particles, so that the obtained composite material still has lithium titanate surface coating Inhomogeneity and insufficient density of the coating layer; on the other hand, the cost of using a two-component chelating agent is high, which greatly increases the manufacturing cost

Method used

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  • A kind of preparation method of lithium titanate-graphene composite negative electrode material
  • A kind of preparation method of lithium titanate-graphene composite negative electrode material

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Embodiment 1

[0024] This embodiment provides a preparation method of lithium titanate-graphene composite negative electrode material, which comprises the following steps:

[0025] Step 1), lithium hydroxide and deionized water are mixed in a mass ratio of 5:95 to form a lithium source solution;

[0026] Step 2), premix ethanol and nitric acid at a volume ratio of 1:0.05, and then add tetra-n-butyl titanate to form a titanium source solution, and the volume ratio of tetra-n-butyl titanate to ethanol is 1:10;

[0027] Step 3), under stirring conditions, according to the ratio of substances Li:Ti=1.0:1, slowly drop the lithium source solution prepared in step 1) into the titanium source solution prepared in step 2) with a dropping funnel, drop The acceleration is 0.1ml / min; after the dropwise addition is completed, adjust the pH value to 8 with ammonia water, and continue to stir for more than 2 hours to obtain a uniformly mixed lithium titanate precursor sol;

[0028] Step 4), under ultraso...

Embodiment 2

[0030] This embodiment provides a preparation method of lithium titanate-graphene composite negative electrode material, which comprises the following steps:

[0031] Step 1), lithium acetate and deionized water are mixed according to a mass ratio of 1:99 to form a lithium source solution;

[0032] Step 2), premix ethanol and acetic acid at a volume ratio of 1:0.01, and then add tetraisopropyl titanate to form a titanium source solution. The volume ratio of tetraisopropyl titanate to ethanol is 1:20;

[0033] Step 3), under stirring conditions, according to the amount ratio Li:Ti=0.6:1, use the dropping funnel to slowly add the lithium source solution prepared in step 1) to the titanium source solution prepared in step 2), drop The acceleration is 1ml / min; after the dropwise addition is completed, adjust the pH value to 8 with ammonia water, and continue to stir for more than 2 hours to obtain a uniformly mixed lithium titanate precursor sol;

[0034] Step 4), under ultrasoni...

Embodiment 3

[0036] This embodiment provides a preparation method of lithium titanate-graphene composite negative electrode material, which comprises the following steps:

[0037] Step 1), lithium oxalate and deionized water are mixed in a mass ratio of 10:90 to form a lithium source solution;

[0038] Step 2), premix ethanol and oxalic acid at a volume ratio of 1:0.1, and then add tetra-n-butyl titanate to form a titanium source solution, and the volume ratio of tetra-n-butyl titanate to ethanol is 1:5;

[0039] Step 3), under stirring conditions, according to the ratio of substances Li:Ti=0.8:1, slowly drop the lithium source solution prepared in step 1) into the titanium source solution prepared in step 2) with a dropping funnel, drop The acceleration is 3ml / min; after the addition is completed, adjust the pH value to 8 with ammonia water, and continue to stir for more than 2 hours to obtain a uniformly mixed lithium titanate precursor sol;

[0040] Step 4), under ultrasonic conditions...

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Abstract

The invention belongs to the technical field of lithium ion battery materials, and particularly relates to a preparation method of a lithium titanate-graphene composite cathode material. The preparation method includes: preparing a lithium source solution and a titanium source solution, slowly adding the lithium source solution into the titanium source solution dropwise, and adjusting pH of mixed liquid to obtain lithium titanate precursor sol; adding graphene, and sintering to obtain the lithium titanate-graphene composite cathode material. The preparation method is low in cost, simple in process and easy-to-control in preparation process. A dropwise adding method is adopted to mix the lithium source solution and the titanium source solution, so that reaction time can be prolonged effectively to lower particle agglomeration, conductivity among particles is improved, and high-rate discharge is facilitated. Therefore, the lithium titanate-graphene composite cathode material prepared by the method can greatly improve conductivity of lithium titanate, high-rate performance of lithium titanate is improved, the surface of lithium titanate can be coated more uniformly, and a coating layer is higher in compactness.

Description

technical field [0001] The invention belongs to the technical field of lithium ion battery materials, and in particular relates to a preparation method of a lithium titanate-graphene composite negative electrode material. Background technique [0002] Lithium-ion power batteries are the heart of new energy vehicles and determine the performance of electric vehicles. Therefore, the safety and cycle life of batteries will become more important, which is the key to the development of the new energy vehicle industry. As we all know, lithium-ion batteries have the advantages of high working voltage, large specific energy, long cycle life, small self-discharge, and no memory effect. They are currently the main power source of electric vehicles. Among them, lithium titanate has good electrochemical performance and safety performance as the anode material of lithium-ion power batteries, which meets the requirements of lithium-ion power batteries to develop toward higher energy densi...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H01M4/36H01M4/485H01M4/583H01M4/62H01M10/0525B82Y30/00
CPCB82Y30/00H01M4/366H01M4/485H01M4/583H01M4/625H01M10/0525Y02E60/10
Inventor 武俊伟白赟顾文亮赵玲张新河
Owner MCNAIR TECH
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