A carbon-coated nano-lithium titanate composite material and its preparation method and application

Abstract

The invention discloses a carbon-coated nano lithium titanate composite material and a preparation method thereof. The preparation method comprises the following steps: 1, preparing nano lithium titanate, namely, respectively preparing micro emulsions of a lithium source and a titanium source, mixing the two types of micro emulsion, standing, centrifuging, alternatively washing with an organic solvent and water, drying, and performing high-temperature calcinations; 2, performing carbon coating on nano lithium titanate, namely, preparing a solution from an organic carbon source, adding lithium titanate granules prepared in the step 1 into the solution, performing ultrasonic dispersion, performing hydrothermal reaction, cooling after the reaction, alternatively washing with the organic solvent and water, filtering, and drying, thereby obtaining the carbon-coated nano lithium titanate composite material. Refining of lithium titanate can be achieved through a micro emulsion method, the solution can be prepared from the carbon source, and carbon coating of the nano lithium titanate can be achieved through hydrothermal reaction, so that a conductive carbon network which is uniform and dense in combination can be formed on the surface of lithium titanate, the conductivity and the large-power charge / discharge property of an electrode material are remarkably improved, and the carbon-coated nano lithium titanate composite material can be used for preparing lithium ion electric containers and lithium ion batteries.

Description

technical field [0001] The invention belongs to the technical field of electrode materials, and in particular relates to a carbon-coated nano-lithium titanate composite material and a preparation method and application thereof. Background technique [0002] Due to the increasingly serious energy and environmental problems, the development and use of clean energy is imminent. With the rapid development of electronic technology, electronic appliances continue to develop rapidly in the direction of miniaturization and high performance. In particular, the wide application of portable electronic devices such as mobile communications, notebook computers and cameras has put forward higher requirements for high-performance energy storage devices, which has led to unprecedented development of lithium-ion capacitors with high power density. [0003] Lithium-ion capacitor is an energy storage device based on the dual energy storage mechanism of supercapacitor and lithium-ion battery. ...

AI Technical Summary

Problems solved by technology

However, during the solid phase sintering process of lithium titanate preparation, the particles are easy to grow and agglomerate seriously, which is not conducive to the preparation of nanoscale lithium titanate

The composite methods mainly include mechanical mixing, high-temperature calcination and coating. Among them, the mechanical mixing method has disadvantages such as long operation time, uneven mixing, and difficulty in controlling the surface shape and particle size of the product. The high-temperature calcination method has high calcination temperature (500-800 ℃ ), agglomeration of particles under high temperature conditions, and the need for inert gas protection. Compared with mechanical mixing and high-temperature calcination, the coating of lithium titanate with carbon with good conductivity is the most common method

However, the existing carbon coating methods have problems such as long operation time, uneven coating, loose bonding, high calcination temperature, and the need for inert gas protection, which is not conducive to the development and utilization of carbon-coated lithium titanate particles

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