Apparatus for preparing cathode active material precursor for lithium secondary batteries and method for preparing the same using the apparatus

Abstract

Provided are an apparatus for preparing a cathode active material precursor for lithium secondary batteries including a cylindrical outer chamber, an inner cylinder that has the same central axis as the outer chamber and is mounted to rotatably move along the central axis, an electric motor to transfer power to rotate the inner cylinder, a reactant inlet disposed on the outer chamber, to add reactants to a space between the outer chamber and the inner cylinder, and an outlet disposed in the outer chamber, to obtain reaction products after reaction in the space between the outer chamber and the inner cylinder, and a method for preparing a cathode active material precursor for lithium secondary batteries using the apparatus.

1 . An apparatus for preparing a cathode active material precursor for lithium secondary batteries, comprising:
 a cylindrical outer chamber;   an inner cylinder that has the same central axis as the outer chamber and is mounted to rotatably move along the central axis;   an electric motor to transfer power to rotate the inner cylinder;   a reactant inlet disposed on the outer chamber, to add reactants to a space between the outer chamber and the inner cylinder; and   an outlet disposed in the outer chamber, to obtain reaction products after reaction in the space between the outer chamber and the inner cylinder.   
     
     
         2 . The apparatus according to  claim 1 , wherein the cylindrical outer chamber is fixed. 
     
     
         3 . The apparatus according to  claim 1 , wherein the outer chamber and the inner cylinder are spaced from each other along the central axis by a predetermined distance. 
     
     
         4 . The apparatus according to  claim 3 , wherein the distance between the outer chamber and the inner cylinder corresponds to a length in the central axial direction of each vortex cell in the form of ring pairs that rotate in opposite directions along the central axial direction due to rotational motion of the inner cylinder. 
     
     
         5 . The apparatus according to  claim 4 , wherein the distance between the outer chamber and the inner cylinder is 0.1 to 100 cm. 
     
     
         6 . The apparatus according to  claim 1 , wherein the central axis is disposed in a horizontal direction with respect to the ground. 
     
     
         7 . The apparatus according to  claim 1 , further comprising one or more outlets along the central axial direction. 
     
     
         8 . The apparatus according to  claim 1 , further comprising a sealing member to block injection of exterior air. 
     
     
         9 . The apparatus according to  claim 8 , wherein the sealing member is an O-ring and the O-ring is mounted outside the central axis. 
     
     
         10 . The apparatus according to  claim 1 , wherein the inner cylinder is rotated at a speed of 10 to 5,000 rpm. 
     
     
         11 . The apparatus according to  claim 1 , further comprising: a reactant flow control pump connected to the reactant inlet, to control flow of the reactants. 
     
     
         12 . The apparatus according to  claim 1 , further comprising: a heat exchanger mounted on the outer chamber, to control a reaction temperature in the space between the outer chamber and the inner cylinder. 
     
     
         13 . A method for preparing a cathode active material precursor for lithium secondary batteries using the apparatus for preparing a cathode active material precursor for lithium secondary batteries according to  claim 1 , comprising:
 adding reactants containing a metal salt aqueous solution, a basic aqueous solution and an aqueous ammonia solution to a reactant inlet (step 1);   rotating the inner cylinder to form ring-shaped vortex pairs that rotate in opposite directions along the central axial direction and to mix the reactants in the space between the outer chamber and the inner cylinder after addition of the reactants in step 1 (step 2);   obtaining a reaction product-containing solution of the reactants mixed, while the reactants moving in the axial direction of the outer chamber in step 2, from the outlet (step 3); and   drying the reaction product-containing solution obtained in step 3 and oxidizing the same in the air (step 4).   
     
     
         14 . The method according to  claim 13 , wherein step 2 further comprises continuously adding the reactants to the reactant inlet during mixing in the space between the outer chamber and the inner cylinder. 
     
     
         15 . The method according to  claim 13 , wherein, in step 2, the inner cylinder was rotated at a speed of 10 to 5,000 rpm and the reactants are mixed at a temperature of 30 to 60° C. and at a pH 10 to 12. 
     
     
         16 . The method according to  claim 13 , wherein, in step 1, the metal salt aqueous solution is a metal salt aqueous solution in which a metal salt containing at least one metal selected from the group consisting of cobalt (Co), manganese (Mn), nickel (Ni), aluminum (Al), magnesium (Mg), copper (Cu), zinc (Zn), iron (Fe), vanadium (V), chromium (Cr), titanium (Ti), tungsten (W) and molybdenum (Mo) is dissolved at a concentration of 1M to 4M in water, and the metal salt is a metal salt such as sulfate, nitrate, acetate, chlorate or phosphate containing at least one metal selected from the group consisting of cobalt (Co), manganese (Mn), nickel (Ni), aluminum (Al), magnesium (Mg), copper (Cu), zinc (Zn), iron (Fe), vanadium (V), chromium (Cr), titanium (Ti), tungsten (W) and molybdenum (Mo). 
     
     
         17 . The method according to  claim 13 , wherein the basic aqueous solution is a 1M to 8M sodium hydroxide aqueous solution or potassium hydroxide aqueous solution. 
     
     
         18 . The method according to  claim 13 , wherein the aqueous ammonia solution is a 15 to 30% aqueous ammonia solution and is added at an amount of 1 to 20% by volume, with respect to the total weight of the mixed solution of the reactants.