Preparation method of battery-grade cobalt carbonate

Abstract

The invention relates to a preparation method of battery-grade cobalt carbonate, which belongs to the field of electrochemistry. The method comprises the following steps: 1) preparing 60-120 g / L of a cobalt salt aqueous solution and 100-400 g / L of an ammonium bicarbonate aqueous solution; 2) adding the ammonium bicarbonate aqueous solution in a reaction vessel, heating the material to the temperature of 40-60 DEG C; 3) under a stirring state, adding the cobalt salt aqueous solution in the reaction vessel; 4) controlling a pH value of a reaction terminal point at 7-7.5; 5) standing and aging the material for more than 1 hour, precipitating an upper layer and extracting mother liquor, keeping a precipitate in the reaction vessel; adding the ammonium bicarbonate aqueous solution in the reaction vessel, heating the material to the temperature of 40-60 DEG C; 6) repeating steps of 3)-5), performing secondary precipitation; and 7) then repeating the steps of 2)-5) until the required granularity is achieved. The method has the advantages of simple operation and easy control, can be widely used for producing battery materials such as cobaltosic oxide and powder metallurgy materials such as cobaltpowder having conventional granularity and large granularity.

Description

technical field [0001] The invention belongs to the technical field of electrochemistry, and in particular relates to a method for preparing battery-grade cobalt carbonate. The large-sized spherical cobalt carbonate produced by the method can be used to produce conventional and large-sized cobalt tetroxide, cobalt powder, and other battery materials and metal materials. Background technique [0002] Cobalt carbonate is used as the precursor of battery materials such as cobalt tetroxide and lithium cobalt oxide, which largely determines the performance of battery materials. Now the particle size of cobalt tetroxide that is used more often is D50=5-10 microns. D50 is calcined from cobalt carbonate of 10-12 microns. This part is mostly used in mid-end battery materials. In recent years, research on battery materials has found that battery materials produced by large-grained cobalt tetroxide have better performance and higher energy efficiency. The voltage platform and compactio...

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Problems solved by technology

[0003] At present, there are many processes for producing cobalt carbonate with a particle size of D50=10-12 microns. There are cobalt liquid and ammonium bicarbonate aqueous solution flowing into the reactor (and addition), and cobalt liquid is added to the method of ammonium bicarbonate aqueous solution (positive addition method). ), the method of adding ammonium bicarbonate aqueous solution to the cobalt liquid (reverse addition) and repeated addition, but these methods are only in the process of producing cobalt carbonate and the cobalt carbonate obtained by addition and forward addition has poor particle size and sphericity. The tapped density is low, although repeated addition can produce cobalt carbonate with uniform particle size and better sphericity, and the tapped density is also good, but the number of repeated precipitations is as many as 20 times, the production time is long, and more equipment is required

[0004] Moreover, these methods are only applicable when producing cobalt carbonate with a particle size of about D50=10 microns, and if it is desired to produce cobalt carbonate with a particle size of D50=15-20 microns or even larger, the above methods cannot be achieved, and the product particle size , poor appearance

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