Method for preparing negative electrode material mono-dispersed nano-crystalline lithium titanate by using nanometer microreactor

Abstract

The invention provides a method for preparing negative electrode material mono-dispersed nano-crystalline lithium titanate (Li4Ti5O12) by using a nanometer microreactor. The method comprises the steps of coating the mono-dispersed TiO2 with an organic acid, adding tetraethyl orthosilicate (TEOS) into a water / ethanol solution containing a surfactant; dispersing the TiO2 coated with the organic acid into the solution, wherein a hydrolysis reaction and a condensation reaction are performed by the TEOS on the oil-water / ethanol interface, fully mixing the hollow TiO2@SiO2 core-shell structure with lithium salt, and calcining at the temperature of 800-1000 DEG C for formation; and dissolving the Li4Ti5O12@Li2SiO3 into a hot NaOH solution to form the mono-dispersed nano-crystalline Li4Ti5O12. In the preparation process, the hollow mesoporous silicon oxide is used as the nanometer microreactor, so that the sizes and the appearances of the particles can be regulated and controlled to prevent from particle aggregation so as to further improve the electromechanical property of the materials.

Description

technical field [0001] The invention designs a nanometer microreactor, in particular utilizes the nanometer microreactor to prepare monodispersed nanocrystalline lithium titanate for lithium ion battery negative electrode materials. Background technique [0002] With the rapid development of smaller, lighter and higher-performance electronic and communication devices, people have put forward higher and higher requirements on the performance of the batteries that power these devices, especially the specific energy. However, the specific capacity of currently commercialized lithium-ion batteries and MH / Ni batteries has been difficult to continue to increase. Therefore, there is an urgent need to develop batteries with higher specific energy. As a high specific energy chemical power source, lithium-ion secondary batteries have been widely used in mobile communications, notebook computers, video cameras, cameras, portable instruments and other fields, and have rapidly developed...

AI Technical Summary

Problems solved by technology

At present, most commercial lithium-ion battery anode materials use carbon anode materials, but carbon anode materials have some defects: they react with the electrolyte to form a surface passivation film during the first discharge process, resulting in the consumption of electrolyte and lower initial Coulombic efficiency. Low; the electrode potential of the carbon electrode is similar to that of metal lithium. When the battery is overcharged, metal lithium may still be precipitated on the surface of the carbon electrode, forming dendrites and causing short circuits, causing safety problems, etc.

Preparation of nanosized Li 4 Ti 5 o 12 , reducing the particle size of the material and shortening the Li + Diffusion path, reducing Li + The purpose of slowing down the electrode polarization is to improve the electrochemical performance of the material, but the nano-sized particles are prone to agglomeration during the charging and discharging process.

As the charge and discharge progress, the electrochemical performance of the material will decrease

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