A kind of preparation method of niobium-doped tungsten-tantalum tricobalt tetroxide

Abstract

The invention discloses a preparation method of niobium, tungsten and tantalum-doped cobalt trioxide and belongs to the technical field of lithium ion batteries. The preparation method is characterized in that the synthetic reaction is performed by taking a certain concentration of cobalt solution as a cobalt source, a sodium hydroxide solution as a precipitating agent, an ammonia aqueous solutionas a complexing agent, a hydrazine hydrate solution as a reducing agent and a niobium, tungsten and tantalum chloride anhydrous alcohol solution as a doping agent; in the reaction process, the niobium, tungsten and tantalum chloride anhydrous alcohol solution is added in a reaction kettle in a dispersive liquid adding manner to participate in the reaction; after the end of the synthetic reaction,a synthetic product is oxidized into hydroxyl cobalt oxide by utilizing a hydrogen peroxide solution under the condition of a certain pH value, and then a mixture is washed, dried and calcined to obtain a niobium, tungsten and tantalum-doped cobalt trioxide product with uniformly-distributed doped elements; the production efficiency is high. The niobium, tungsten and tantalum-doped cobalt trioxide product prepared by the preparation method disclosed by the invention has a doping amount of 0.5-1 percent, has the uniformly-distributed doped elements, has a laser particle size of 15-20 mum, a tap density of more than or equal to 2.5 g / cm<3> and a specific surface area of 1.0-3.0 m<2> / g and has a massive or nearly-spherical appearance.

Description

technical field [0001] The invention belongs to the technical field of lithium ion batteries, in particular to a method for preparing niobium-doped tungsten-tantalum tricobalt tetroxide used for preparing lithium cobalt oxide, a cathode material of lithium-ion batteries. Background technique [0002] The lithium-ion battery prepared with lithium cobaltate as the positive electrode material has the characteristics of light weight, large capacity, high specific energy, high working voltage, stable discharge, suitable for high current discharge, good cycle performance, and long life. It is mainly used in 3C digital field. [0003] Lithium cobalt oxide is developing in the direction of high voltage, high compaction, and high cycle performance. Therefore, the requirements for the raw material cobalt tetroxide are getting higher and higher. co 3 o 4 It is a functional material with special structure and properties, conventional Co 3 o 4 The market is already facing the status...

AI Technical Summary

Problems solved by technology

However, when this method is used to prepare niobium, tungsten, and tantalum tricobalt tetroxide doped with high-valence and large atomic weight elements, there is the problem that niobium, tungsten, and tantalum chloride are easily hydrolyzed as wet dopants, resulting in the formation of niobium, tungsten, and tantalum elements. The precipitation is not uniform, which leads to the problem of uneven distribution of doping elements in cobalt tetroxide

In addition, the cobalt compound is very easy to oxidize, and the oxidized cobalt compound will hinder the rapid growth of the synthetic product. Therefore, this method also has the problem of low production efficiency.

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