Method for preparing carbon-coating type lithium titanate for lithium ion battery

A carbon-coated lithium titanate and lithium-ion battery technology, which is applied in the field of lithium-ion battery anode materials, can solve problems such as poor electronic conductivity and poor rate charge and discharge performance, achieve firm and tight contact, improve electronic conductivity, Effect of improving rate charge and discharge performance

Inactive Publication Date: 2009-03-04
TIANJIN B&M SCI & TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0004] However, since the lithium titanate material is a semiconductor material, the electronic conductivity is poor, and the rate charge and discharge performance is not good.

Method used

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  • Method for preparing carbon-coating type lithium titanate for lithium ion battery
  • Method for preparing carbon-coating type lithium titanate for lithium ion battery
  • Method for preparing carbon-coating type lithium titanate for lithium ion battery

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preparation example Construction

[0029] First, if figure 1 Shown, preparation method of the present invention comprises the following steps:

[0030] 1) Lithium salt and titanium dioxide are weighed according to the ratio of molar ratio Li:Ti=(0.81~0.87):1, and described lithium salt is lithium carbonate, lithium hydroxide, lithium oxide, lithium nitrate, lithium phosphate, lithium chlorate and one or several kinds of lithium oxalate, then add dispersant distilled water, absolute ethanol or acetone, the mass ratio of dispersant to ball milling mixture is (1~3):4, fully mix by ball milling, ball milling time is 2 ~10 hours, and then vacuum-dried at 80~120° C. for 12~36 hours to prepare the precursor (S10);

[0031] 2) Calcining the prepared precursor at 750-1000°C for 8-20 hours to prepare lithium titanate (S20);

[0032] 3) Coating a carbon source material soluble in absolute ethanol or acetone on the surface of the prepared lithium titanate (S30) by dipping and evaporating to dryness, the carbon source mat...

Embodiment 1

[0039] Take lithium carbonate 25.9g, TiO 2 66.1g, 45ml of dispersant water, placed in a ball mill jar, at a speed of 40Hz, mixed by ball mill for 4h, and dried to obtain the precursor; the precursor was roasted in a muffle furnace at a temperature of 900°C for 14h to obtain titanium Lithium Oxide. The median diameter D50 of the product particles was measured to be 16.1 μm, and the specific surface area was 2.9 m 2 / g.

[0040] The selected carbon source material is phenolic resin, take 5.0g of phenolic resin, add it to 100ml of absolute ethanol, 70oC water bath, mechanically stir for 30 minutes to fully dissolve the resin, then slowly add 30g of lithium titanate powder, and stir quickly until the ethanol evaporates to dryness So far, the obtained paste is placed in a tube furnace and roasted under the protection of argon, the roasting temperature is 850°C, and the roasting time is 2h. The obtained product is denoted as carbon-coated lithium titanate material I. It is measu...

Embodiment 2

[0042] Take LiOH·H 2 O11.1g, TiO 2 26.1g, 5.0g of phenolic resin, 17ml of anhydrous ethanol as a dispersant, placed in a ball mill jar, with a speed of 40Hz, ball milled for 4h, dried to obtain the precursor, the precursor was placed in a tube furnace for roasting, nitrogen protection, temperature 900° C. for 14 hours to obtain carbon-coated lithium titanate material II. It is measured that the coating amount of carbon in the carbon-coated lithium titanate material II is 5.0%, the median diameter D50 of the product particles is 11.4 μm, and the specific surface is 3.8 m 2 / g.

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Abstract

The invention discloses a preparation method of carbon-coated lithium titanate used for a lithium ion battery; the method comprises the following steps: (1) lithium salt and titanium dioxide are weighted according to proportion, a dispersing agent is added, a ball milling method is used for mixing fully and then the obtained mixture is dried in vacuum, thus obtaining a precursor; (2) the obtained precursor is roasted for 8 to 20 hours at the temperature of 750 to 1000 DEG C so as to prepare lithium titanate; (3) carbon source materials are coated on the surface of the prepared lithium titanate by a dipping and steaming method; and (4) the lithium titanate coated with the carbon source materials is placed in a tubular furnace, and is roasted for 0.5 to 5 hours at the temperature of 750 to 1000 DEG C under the protection of inert gas so as to obtain the carbon-coated lithium titanate. The preparation method of the invention forms chemically coated carbon on the surface of the lithium titanate by the pyrolytic reaction of the carbon-coated materials, and the surface contact of the coated carbon and the lithium titanate material is more firm and tight, thus improving the electron conductivity of the materials greatly and enhancing the charge and discharge performance of magnification of the materials.

Description

technical field [0001] The invention relates to lithium ion battery negative electrode materials, in particular to a method for preparing carbon-coated lithium titanate for lithium ion batteries by chemical pyrolysis of carbon source materials. Background technique [0002] At present, the research focus of negative electrode materials for lithium-ion batteries is developing in the direction of power battery materials with high specific capacity, high charge-discharge efficiency, high cycle performance, and high-rate charge-discharge resistance. The existing commercial lithium-ion battery negative electrode material is carbon negative electrode material, but carbon negative electrode material has some defects, such as: SEI film (solid electrolyte interfacial film) is formed during the first discharge process, resulting in irreversible capacity loss, high temperature may cause battery Failure or safety problems, poor high-current charging and discharging performance, etc., th...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01M4/04
CPCY02E60/10
Inventor 徐宁吕菲李磊吴孟涛
Owner TIANJIN B&M SCI & TECH
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