Nickel manganese composite hydroxide particles and manufacturing method thereof, cathode active material for a non-aqueous electrolyte secondary battery and manufacturing method thereof, and a non-aqueous electrolyte secondary battery

Abstract

Provided are nickel manganese composite hydroxide particles that are a precursor for forming cathode active material including lithium nickel manganese composite oxide having hollow structure of particles having a small and uniform particle size for obtaining a non-aqueous electrolyte secondary battery having high capacity, high output and good cyclability. When obtaining the nickel manganese composite hydroxide particles from a crystallization reaction, an aqueous solution for nucleation, which includes at least a metallic compound that contains nickel and a metallic compound that contains manganese, and does not include a complex ion formation agent that forms complex ions with nickel, manganese and cobalt, is controlled so that the temperature of the solution is 60° C. or greater, and so that the pH value that is measured at a standard solution temperature of 25° C. is 11.5 to 13.5, and after nucleation is performed, an aqueous solution for particle growth, which includes the nuclei that were formed in the nucleation step and does not substantially include a complex ion formation agent that forms complex ions with nickel, manganese and cobalt, is controlled so that the temperature of the solution is 60° C. or greater, and so that the pH value that is measured at a standard solution temperature of 25° C. is 9.5 to 11.5, and is less than the pH value in the nucleation step.

What is claimed is: 
     
         1 . A cathode active material for a non-aqueous electrolyte secondary battery, the cathode active material comprising:
 spherical secondary particles formed with aggregated primary particles of a lithium nickel manganese composite oxide, the lithium nickel manganese composite oxide expressed by the general formula
   Li 1+u Ni x Mn y Co z M t O 2    
   wherein
 —0.05≦u≦0.50, 
 x+y+z+t=1, 
 0.3≦x≦0.7 
 0.1≦y≦0.55, 
 0≦z≦0.4, 
 0≦t≦0.1 
 M is an added element selected from one or more elements from among Mg, Ca, Al, Ti, V, Cr, Zr, Nb, Mo and W; 
   wherein the secondary particle comprise
 a layered hexagonal crystalline structure, 
 an average particle size of 2 to 8 μm, 
 a value of 0.60 or less of index (d90−d10)/average particle size) indicating an extent of a particle size distribution, 
 a specific surface area of 1 to 1.8 m 2 /g, and 
 a hollow structure comprising a hollow section formed in a center section of the secondary particles and an outer shell section on the outside of the hollow section, the outer shell section formed with the aggregated primary particles and the thickness of the outer shell section being 0.5 to 2.5 μm to allow electrolyte to enter inside from the particle boundaries or space between the primary particles of the outer shell and to allow lithium to be inserted and removed at a reactive interface on a surface of the primary particles on the hollow section side; and 
 a ratio of the thickness of the outer shell section with respect to the particle size of the lithium nickel manganese composite oxide particles is 0.05 to 0.45. 
   
     
     
         2 . The cathode active material for a non-aqueous electrolyte secondary battery of  claim 1 , wherein the average particle size is 3 to 6 μm, and the specific surface area is 1 to 1.6 m 2 /g.