Reactor for preparing precursor of lithium composite transition metal oxide and method for preparing precursor

Abstract

Disclosed is a reactor for preparing a precursor of lithium composite transition metal oxide for lithium secondary batteries, the reactor having a closed structure including a stationary hollow cylinder; a rotary cylinder having the same axis as the stationary hollow cylinder and an outer diameter smaller than an inner diameter of the stationary hollow cylinder, an electric motor to generate power, enabling rotation of the rotary cylinder, a rotation reaction area disposed between the stationary hollow cylinder and the rotary cylinder, wherein ring-shaped vortex pairs that are uniformly arranged in a rotation axis direction and rotate in opposite directions are formed in the rotation reaction area, and an inlet through which a reactant fluid is fed into the rotation reaction area and an outlet through which the reactant fluid is discharged from the rotation reaction area.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application is a continuation of International Application No. PCT / KR2012 / 007058, filed Sep. 4, 2012, which claims the benefit of Korean Patent Application No. 10-2012-0010134, filed Feb. 1, 2012, the disclosures of which are incorporated herein by reference.TECHNICAL FIELD[0002]The present invention relates to a reactor for preparing a precursor of lithium composite transition metal oxide and a method for preparing the precursor.BACKGROUND ART[0003]Technological development and increased demand for mobile equipment have led to a rapid increase in the demand for secondary batteries as energy sources. Among these secondary batteries, lithium secondary batteries having high energy density and voltage, long lifespan and low self-discharge are commercially available and widely used.[0004]Among components of lithium secondary batteries, a cathode active material has an important role in determining capacity and performance of batteries.[0...

AI Technical Summary

Benefits of technology

The present invention provides a method for preparing a material without adding nitrogen, which reduces costs and improves efficiency. This is achieved by performing the preparation method in a non-nitrogen atmosphere. Additionally, no reducing agent is needed, which further reduces costs.

Problems solved by technology

However, cobalt used for LiCoO2 is a metal, so-called “rare metal”, which is low in deposits and are produced in limited areas, thus having an unstable supply.

Also, LiCoO2 is disadvantageously expensive due to unstable supply of cobalt and increased demand of lithium secondary batteries.

The lithium composite transition metal oxide exhibits superior electrochemical properties through combination of high capacity of lithium nickel oxide (LiNiO2), thermal stability and low price of manganese in layered-structure lithium manganese oxide (LiMnO2), and stable electrochemical properties of LiCoO2, but is not easy to synthesize through a simple solid reaction.

However, a conventional coprecipitation reactor, for example, a continuous stirred tank reactor (CSTR) has a problem of low retention time taken for controlling the structure of composite transition metal precursors.

Also, due to long retention time, precursor particles prepared using a conventional coprecipitation reactor have a wide particle size distribution and a non-uniform particle shape and contain a great amount of impurities.

Also, in a case in which precursor particles are prepared using a conventional coprecipitation reactor, it is disadvantageously difficult to adjust the mean particle size of the precursor particles to a level smaller than 6 μm.

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