Nanometer lithium titanate/graphene composite negative electrode material and preparation process thereof

A nano-lithium titanate and graphene composite technology, which is applied in battery electrodes, non-aqueous electrolyte battery electrodes, electrical components, etc., can solve problems such as difficulty in realizing large-scale industrial production, limiting the wide application of composite materials, and complex synthesis processes. Achieve the effect of improving ion transport capacity, good electrochemical performance, and simple process

Inactive Publication Date: 2012-03-14
INST OF METAL RESEARCH - CHINESE ACAD OF SCI
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0005] At present, the composite method of lithium titanate and conductive materials mostly adopts the sol-gel method for in-situ synthesis. However, due to the need to add a large amount of organic compounds in the preparation process, the synthesis process is complicated, and waste pollution will be produced to varying degrees, so it is difficult to achieve large-scale industrial production, which limits the wide application of composite materials

Method used

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  • Nanometer lithium titanate/graphene composite negative electrode material and preparation process thereof
  • Nanometer lithium titanate/graphene composite negative electrode material and preparation process thereof
  • Nanometer lithium titanate/graphene composite negative electrode material and preparation process thereof

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preparation example Construction

[0037] (1) Preparation of nano-lithium titanate: uniformly mix titanium dioxide and lithium source, the molar ratio of lithium to titanium is N (Li) :N (Ti) =(0.8~0.9):1, titanium dioxide and lithium source are carried out ball milling by planetary ball mill, carry out wet method ball milling, ball milling time is 1~48 hours, after drying, titanium dioxide and lithium source mixed powder in protective atmosphere Calcining at 600-1100°C for 1-48 hours, and cooling to obtain micron lithium titanate powder. Then put the micron lithium titanate obtained after calcination into an ultrafine mill, and wet ball mill it for 10 to 240 minutes under the condition of a rotating speed of 1000 to 10,000 rpm, take it out, wash it with absolute ethanol, and dry it to obtain Nano lithium titanate powder.

[0038] (2) Synthesis of the precursor of the composite negative electrode material: the nano-lithium titanate powder prepared in step (1) is added to the graphene solution with a concentra...

Embodiment 1

[0042] Select lithium carbonate as the lithium source, and mix lithium carbonate and anatase titanium dioxide according to the molar ratio of lithium to titanium N (Li) :N (Ti) = 0.82: 1 mixed evenly, adding absolute ethanol, the solid content was 35wt% during ball milling, ball milled on a planetary ball mill at a speed of 400 rpm for 12 hours, heated and dried at a constant temperature at 100°C, and then dried under an argon atmosphere , Calcinate the mixed powder of titanium dioxide and lithium source at 800°C for 12 hours, and take it out when it is cooled to below 100°C with the furnace to obtain micron lithium titanate powder.

[0043] Put the above-mentioned micron lithium titanate powder into an ultrafine ball mill, add absolute ethanol, the solid content is 25wt% during ball milling, and ball mill at a speed of 2200 rpm for 90 minutes. After the ball milling, heat and dry at a constant temperature of 80°C. The nano lithium titanate powder is obtained.

[0044] Parti...

Embodiment 2

[0051] Nanoscale lithium titanate was prepared in the same manner as in Example 1.

[0052] The difference from Example 1 is that:

[0053] Weigh 60 mg of uniformly dispersed graphene solid powder, mix it with 100 ml of N-methylpyrrolidone, and disperse it ultrasonically for 10 minutes.

[0054] Weigh 1.94g of nano-lithium titanate powder and add it to the graphene solution, wherein graphene accounts for 3% of the total weight of the composite negative electrode material, and lithium titanate accounts for 97% of the total weight of the composite negative electrode material. After magnetically stirring for 30 minutes to mix evenly, the mixture solution was ultrasonically dispersed for 30 minutes. Spray drying at 200-250° C. to obtain composite negative electrode material precursor powder.

[0055] Calcining the obtained composite anode material precursor in an argon atmosphere, raising the temperature to 400° C., keeping it warm for 20 hours, and cooling in the furnace to obt...

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Abstract

The invention relates to the field of negative electrode materials of lithium ion batteries, and specifically to a nanometer lithium titanate/graphene composite negative electrode material and a preparation process thereof. According to the invention, micron-sized lithium titanate prepared by the solid phase method is subjected to ultrafine ball milling to obtain nanometer powder, and the nanometer lithium titanate powder and graphene are uniformly compounded and subjected to heat treatment so as to obtain a high performance lithium ion battery negative electrode material; the invention is characterized in that uniform distribution of graphene in the nanometer lithium titanate powder is realized through in situ compounding; the weight of graphene in the composite negative electrode material accounts for 0.5 to 20%, and the weight of lithium titanate accounts for 80 to 99.5%. The lithium ion battery negative electrode material has good electrochemical performance, 1C capacity greater than 165 mAh/g, 30C capacity greater than 120 mAh/g and 50C capacity greater than 90 mAh/g. Nanometer lithium titanate in the lithium ion battery negative electrode material prepared in the invention has high phase purity; the preparation process of the material is simple and is easy for industrial production.

Description

technical field [0001] The invention relates to the field of negative electrode materials for lithium ion batteries, in particular to a nanometer lithium titanate / graphene composite negative electrode material and a preparation method thereof. Background technique [0002] In recent years, lithium-ion batteries have been widely used in mobile communications, digital cameras, notebook computers and other portable electronic devices, as well as military defense and aerospace fields due to their outstanding properties such as high energy density, long cycle life, and low self-discharge. With the rapid development of lithium-ion battery technology, lithium-ion power batteries used as power are attracting more and more attention. Well-known automobile companies at home and abroad have also begun to develop high-power batteries that can meet the needs of electric vehicles and hybrid vehicles. , High-rate new lithium-ion battery electrode materials. [0003] As a negative electrod...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01M4/13B02C17/00H01M4/139
CPCY02E60/10
Inventor 成会明闻雷石颖李峰
Owner INST OF METAL RESEARCH - CHINESE ACAD OF SCI
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