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.

1 . A reactor for preparing a precursor of lithium composite transition metal oxide for lithium secondary batteries, the reactor having a closed structure comprising:
 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,   wherein a ratio of a distance between the stationary hollow cylinder and the rotary cylinder to the outer diameter of the rotary cylinder is higher than 0.05 and lower than 0.4.   
     
     
         2 . The reactor according to  claim 1 , wherein a kinematic viscosity of reactant fluid is 0.4 to 400 cP and power consumed per unit weight thereof is 0.05 to 100 W/kg. 
     
     
         3 . The reactor according to  claim 1 ,
 wherein a critical Reynolds number of the vortex pairs is 300 or more.   
     
     
         4 . The reactor according to  claim 1 , wherein the inlet comprises two or more inlets. 
     
     
         5 . The reactor according to  claim 4 , wherein the two or more inlets are arrayed in a line by a predetermined distance in a direction of the outlet. 
     
     
         6 . A method for preparing transition metal composite hydroxide particles using the reactor according to  claim 1  the method comprising:
 injecting raw materials comprising an aqueous solution of two or more transition metal salts and an aqueous solution of a complex-forming additive, and a basic aqueous solution for maintaining pH of an aqueous solution of the raw materials within a range of 10 to 12, into the rotation reaction area of the reactor through the inlet; and 
 performing coprecipitation reaction under a non-nitrogen atmosphere for 1 to 6 hours. 
 
     
     
         7 . The method according to  claim 6 , wherein the aqueous solution of a complex-forming additive is present in an amount of 0.01 to 10% by weight, based on the total amount of the two or more transition metal salts. 
     
     
         8 . The method according to  claim 7 , wherein the aqueous solution of a complex-forming additive is an aqueous ammonia solution. 
     
     
         9 . The method according to  claim 6 , wherein the transition metal salt is sulfate and/or nitrate. 
     
     
         10 . The method according to  claim 9 , wherein the sulfate comprises one or two or more selected from the group consisting of nickel sulfate, cobalt sulfate and manganese sulfate, and the nitrate comprises one or two or more selected from the group consisting of nickel nitrate, cobalt nitrate and manganese nitrate. 
     
     
         11 . The method according to  claim 6 , wherein the transition metal composite hydroxide is a compound represented by Formula 1 below:
   M(OH 1-x ) 2   (1)
   wherein M comprises two or more selected from the group consisting of Ni, Co, Mn, Al, Cu, Fe, Mg, B, Cr and transition metals of the second period; and 0≦x≦0.8.   
     
     
         12 . The method according to  claim 11 , wherein M comprises two kinds of transition metals or all selected from the group consisting of Ni, Co and Mn.