Preparation method of large-particle narrow-distribution aluminum doped tricobalt tetroxide

Abstract

The invention relates to the technical field of lithium ion batteries, in particular to a preparation method of large-particle narrow-distribution aluminum doped tricobalt tetroxide. The method includes a stage of continuously synthesizing large-particle narrow-distribution aluminum doped cobalt carbonate, and a stage of calcining the large-particle narrow-distribution aluminum doped cobalt carbonate. A large-particle cobalt carbonate precursor prepared by continuous centrifugation to improve the solid content, the continuous synthesis method and a special aluminum salt method in the cobalt carbonate wet-process synthesis stage is dense, narrow in particle size distribution, good in sphericity and uniform in aluminum element distribution. Through a three-step calcination method, the temperature in the first step is 180-250 DEG C and the cobalt carbonate is partially decomposed to form a micropore channel; the cobalt carbonate is completely decomposed in the second step in which the temperature is 300-500 DEG C; in the third step, the temperature is 650-800 DEG C, particle surfaces are densified, the content of the cobaltous phase is lower, the crystal form is more complete, and thelarge-particle narrow-distribution aluminum doped tricobalt tetroxide is formed. .

Description

technical field [0001] The invention relates to the technical field of lithium-ion batteries, in particular to a method for preparing large-particle narrow-distribution aluminum-doped tricobalt tetroxide. Background technique [0002] Lithium-ion batteries are favored because of their high voltage, high energy density, long cycle life, and low environmental pollution. In recent years, with the further growth of demand for small portable power sources, good opportunities have been created for the development of the lithium-ion battery industry. The rapid development of the lithium-ion battery industry has driven lithium cobaltate, nickel-cobalt lithium With the rapid development of cathode materials such as lithium, the demand for cathode materials for lithium-ion batteries has also increased significantly. Especially in recent years, with the rapid development of the digital product industry, people's demand for high energy density lithium-ion batteries is increasing. Lith...

AI Technical Summary

Problems solved by technology

However, the lithium cobalt oxide prepared by the existing technology has the disadvantages of rapid decrease in specific capacity and poor cycle performance under the voltage condition of 4.45V and above.

In order to improve the performance of lithium cobalt oxide, lithium cobalt oxide material is doped with aluminum element. The existing doping method is to wrap a layer of aluminum salt in the form of coating after the synthesis of cobalt carbonate precursor, and then aluminum element is added when cobalt carbonate is calcined. Infiltrated into the interior of cobalt tetroxide, but the distribution of aluminum element in the interior of cobalt tetroxide is uneven, which in turn affects the uniformity of aluminum element distribution in lithium cobalt oxide, and seriously affects the stability of lithium cobalt oxide structure at 4.45V and above

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