Method for preparing ball shape mixed lithium cobaltate and it prepared ball shape mixed lithium cobaltate

Abstract

The invention provides spheral doping lithium cobaltate prepn. method, high-activity doping colbalt hydroxide is prepared by electrolyzing metal cobalt, then to be fired in oxidating atmosphere to produce sphere cobalt orthoplumbate, finally, the spheral cobalt orthoplumbate and lithium carbonate are mixed first to produce high-activity doping lithium cobalate. By the invention, requirement of purity for raw material used to produce doping lithium cobalate is lower to reduce prodn. costs and increase electrochemistry performance of products.

Description

technical field [0001] The invention belongs to positive electrode materials of lithium ion batteries, in particular to a method for preparing spherical high-density doped lithium cobaltate and the prepared spherical doped lithium cobaltate. Background technique [0002] Lithium-ion battery is a new type of power source, it has many advantages such as high voltage, high specific energy, safety and environmental protection, so it is being widely accepted by people. Lithium cobalt oxide is the most widely used material in the positive electrode material of lithium ion batteries. Compared with other positive electrode materials, it has the advantages of high open circuit voltage, large specific energy, long cycle life and easy synthesis, and can be quickly charged and discharged. [0003] At present, cobalt tetroxide is mainly used to prepare lithium cobalt oxide, and co-precipitation of soluble cobalt salt and carbonate (or oxalate) is mostly used to prepare cobalt carbonate (...

AI Technical Summary

Problems solved by technology

One of the disadvantages of existence is that because cobalt carbonate is prepared by a liquid phase reaction method, the purity of raw materials is extremely high, and the nucleation speed of cobalt carbonate (or cobalt oxalate) is extremely fast because the reaction is difficult to control, so its product particle size It is difficult to control the particle size, so that the particle size is finer, and the tap density of the lithium cobaltate particles obtained by this method is low, which leads to an increase in the battery volume

The second disadvantage is that the particle size distribution of lithium cobaltate prepared by this method is large and uneven, which increases the internal resistance of the battery to a certain extent.

Three of shortcoming is to adopt this method, because the content of impurity such as K, Na contained in the cobalt carbonate precipitation is more, therefore unavoidably cause impurity such as K, Na in the cobalt tetroxide obtained by calcining are more, not only cause The liquidity is poor, and the cost of third-degree treatment is relatively high, which increases the cost