Preparation method of anode active material

Abstract

The invention provides a preparation method of an anode active material, which comprises the steps of: a, adding a titanium source and an organic carbon source in an organic solution with the pH value of 0-6 to prepare a mixture solution; b, adding an oxidizing agent in the mixture solution, reacting for 1-24h at a temperature of 20-80 DEG C, then separating and settling, washing with water, drying to obtain a titanium-containing precursor; and c, carrying out mixing and ball-milling on the titanium-containing precursor obtained in the step b and a lithium source, and then roasting in an inert gas. A lithium titanate composite material prepared by adopting the method disclosed by the invention has less impurity phases; the prepared nanometer lithium titanate particles are attractive in appearance; and the preparation method has the advantages of short time, low energy consumption, low cost, high yield, uniform particles of the prepared material, stable performance of the prepared material, simple and controllable process, and capability of realizing massive industrialized clean production.

Description

technical field [0001] The invention relates to a preparation method of a negative electrode active material. Background technique [0002] Lithium-ion batteries have the advantages of high energy density (150-200Wh / kg), high working voltage, low self-discharge, long life, no memory effect, and environmental friendliness. They have been widely used in mobile communications, notebook computers, video cameras, cameras, portable Instrumentation and other fields are also the preferred supporting power sources for electric vehicles and space power sources that have been vigorously researched by various countries, and have become the first choice for alternative energy sources. [0003] Advanced electrode materials have become the core technology for the replacement of lithium-ion batteries. The existing commercial negative electrode active materials are generally carbon materials, and carbon materials cannot meet the needs of current high-power electrical equipment. For example,...

AI Technical Summary

Problems solved by technology

The solid-phase synthesis method is simple to operate and easy to industrialize; however, it is difficult to finely control the properties of the product, it is difficult to prepare fine particles, and the conductivity of the material is poor; and the reaction control is also difficult, and there are incomplete and inhomogeneous reactions, and generally there will be residual TiO in the product. 2 or monoclinic Li 2 TiO 3 , the capacity fades quickly in actual use, which is not conducive to commercial applications

Liquid-phase synthesis can synthesize nano-scale ultrafine powders. Generally, organic precursors are used as raw materials, and sols are formed through hydrolysis or alcoholysis of raw materials. Solvents are volatilized under certain conditions, and aging loses fluidity to obtain gels, which are then heat-treated. To obtain the final product, the method is complex in process, high in cost, and low in yield, which is not conducive to large-scale process production, and is also difficult to prepare relatively pure lithium titanate

[0006] The prior art also discloses TiCl 4 Or titanyl sulfate is mixed with graphite under acidic conditions, and then kerosene is used as the dispersion medium to prepare the precursor with ammonia water and sinter with lithium source to prepare spherical carbon-doped lithium titanate, but the product obtained by this method has many impurity phases and impurities. Large mass, easy to contain rutile TiO 2 Moreover, the amount prepared each time will be limited, so it is not suitable for large-scale production and promotion. At the same time, the prepared particles will agglomerate, and the size of the precipitated particles should not be controlled. The particle size of the synthesized precursor is still large, and the particle size is not uniform, and the particle size distribution width is wide Large, not only the conductivity of the material is still not ideal, but also affects the consistency and stability of the final material; resulting in a long diffusion path for lithium ions, unsatisfactory electrochemical performance, and serious attenuation of specific capacity

Images