Composite material of lithium tetrachloroaluminate and carbon nanotube coated lithium titanate, and preparation method and application of composite material

Abstract

The invention relates to a composite material of lithium tetrachloroaluminate and carbon nanotube coated lithium titanate, and a preparation method and an application of the composite material. The composite material comprises composite particles and a carbon nanotube layer, wherein the composite particles are composed of a lithium titanate core and a lithium tetrachloroaluminate coating layer coating a surface of the core, and the carbon nanotube layer coats the surface of the composite particles. The method comprises steps of (1) alternately depositing lithium chloride and aluminum trichloride on surfaces of lithium titanate particles by adopting the ALD (Atomic Layer Deposition) method, and forming the lithium tetrachloroaluminate coating layer on the surfaces of the lithium titanate particles to obtain the composite particles; and 2) adding the composite particles and carbon nanotubes into water-alcohol mixed solvent, and carrying out ball milling and spray drying to obtain the composite material. The composite material is advantaged in that the composite material is of a double-layer coating structure, is stable in structure, and has characteristics of high gram volume, good rate capability and conductivity, excellent cycle performance and good lithium intercalation and deintercalation capabilities. The method disclosed by the invention is simple to operate and environment-friendly, and industrial production is easy to realize.

Description

technical field [0001] The invention belongs to the field of lithium ion battery negative electrode materials, and relates to a composite material of lithium tetrachloroaluminate and carbon nanotube-coated lithium titanate, a preparation method thereof, and a lithium ion battery containing the composite material. Background technique [0002] Lithium-ion batteries include electrode materials, electrolytes, diaphragms, casings, etc. Compared with other types of batteries, lithium-ion batteries are considered to be It is an excellent power source for power batteries and energy storage systems. As a platform for battery charge and discharge, the performance of electrode materials is crucial to lithium batteries. [0003] Commercial lithium-ion batteries mainly use carbon as the negative electrode material. Since the potential of the carbon negative electrode material is close to that of metal lithium after lithium intercalation, when the battery is overcharged, metal lithium d...

AI Technical Summary

Problems solved by technology

The advantages of the solid-phase method are simple process, low equipment requirements, low cost, and easy realization of large-scale industrial production; The requirements for raw materials and equipment are high, and it is not easy to produce on a large scale; the properties of the samples obtained by the sol-gel method and the chemical precipitation method are improved compared with the previous two methods, but the process is long and the cost of raw materials is high, so it is not easy to produce on a large scale; Therefore, the solid phase reaction method is more suitable for industrial production

However, the electrical conductivity of the lithium titanate negative electrode material is very poor, resulting in a very low rate performance of the battery prepared by it. At the same time, the lithium battery with lithium titanate as the negative electrode has the problem of flatulence during use. Yanbing He, Baohua Li, Ming Liu et al. Gassing in Li 4 Ti 5 o 12 -based batteries and its remedy" analyzed the reasons in detail. The flatulence is mainly due to the reaction between the surface of lithium titanate particles and the electrolyte to generate H 2 , CO 2 and CO

Images