Method and apparatus for producing positive electrode active material for secondary battery

Abstract

The present invention provides a method for producing a positive electrode active material for a secondary battery, the method comprising the steps of: 1) forming positive electrode active material precursor particles while feeding a reaction solution into a batch type reactor, the reaction solution comprising: a transition metal-containing solution containing transition metal positive ions; an aqueous basic solution; and an ammonium ion-containing solution; 2) discharging a portion of the reaction slurry inside the reactor when the reactor is full, and feeding the discharged reaction slurry into a hydrocyclone; 3) centrifugally separating the reaction slurry, fed into the hydrocyclone, into a supernatant and a concentrated reaction slurry containing the positive electrode active materialprecursor particles; and 4) discharging the supernatant to the outside, and re-feeding the concentrated reaction slurry into the reactor to regrow the positive electrode active material precursor particles.

Description

technical field [0001] Cross References to Related Applications [0002] This application claims the benefit of Korean Patent Application No. 10-2018-0024859 filed in the Korean Intellectual Property Office on February 28, 2018, the disclosure of which is incorporated herein by reference in its entirety. technical field [0003] The invention relates to a method and equipment for preparing positive electrode active materials for secondary batteries. Background technique [0004] With the technological development and increase in demand for mobile devices, the demand for secondary batteries as energy sources has significantly increased. Among these secondary batteries, lithium secondary batteries having high energy density, high voltage, long cycle life, and low self-discharge rate have been commercialized and widely used. [0005] Lithium transition metal oxides have been used as positive electrode active materials for lithium secondary batteries, and among these oxide...

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Problems solved by technology

[0009] Generally, the advantage of the CSTR method is that it is easy to control the metal composition ratio, but the limitation of the CSTR method is that since the raw material input and the product discharge are performed simultaneously and continuously, the retention time and the reaction time of the positive electrode active material formed in the reactor may vary. Varies, and the resulting particles may be non-uniform in size and composition

[0010] Thus, there is a tendency to adopt a batch method that can facilitate particle size control and prepare a positive electrode active material precursor with a uniform particle size, but it is difficult to prepare a positive electrode active material with a uniform particle size distribution even with a batch reactor precursors, and the productivity may be significantly lower compared to the CSTR method

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