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 comprising 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.

1 . A method for manufacturing nickel manganese composite hydroxide particles by a crystallization reaction such that the nickel manganese composite hydroxide particles can be expressed by the general formula Ni x Mn y Co z M t (OH) 2+a (where x+y+z+t=1, 0.3≦x≦0.7, 0.1≦y≦0.55, 0≦z≦0.4, 0≦t≦0.1, 0≦a≦0.5, and M is one or more added element that is selected from among Mg, Ca, Al, Ti, V, Cr, Zr, Nb, Mo and W),
 the manufacturing method comprising: 
 a nucleation step of controlling 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, 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 generating nuclei as center sections comprising fine primary particles; and 
 a particle growth step of controlling 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, 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, and growing an outer shell section comprising primary particles having a plate shape or needle shape that is larger than the fine primary particles on an outer surface of the nuclei. 
 
     
     
         2 . The manufacturing method for manufacturing nickel manganese composite hydroxide particles according  claim 1  wherein
 in the nucleation step and particle growth step, the oxygen concentration inside the reaction tank is controlled to be 10% by volume or less. 
 
     
     
         3 . The manufacturing method for manufacturing nickel manganese composite hydroxide particles according to  claim 1  wherein
 the pH value of the aqueous solution for nucleation after the nucleation step has finished is adjusted and the resulting aqueous solution is used as the aqueous solution for particle growth. 
 
     
     
         4 . The manufacturing method for manufacturing nickel manganese composite hydroxide particles according to  claim 1  wherein
 a solution that is obtained by adding an aqueous solution, which contains the nuclei formed in the nucleation step, to a component adjustment aqueous solution, which is separate from the aqueous solution for nucleation in which the nuclei were formed, does not substantially include a complex ion formation agent that forms complex ions with nickel, manganese and cobalt, and is controlled so that the solution temperature 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 lower than the pH value in the nucleation step, is used as the aqueous solution for particle growth. 
 
     
     
         5 . The manufacturing method for manufacturing nickel manganese composite hydroxide particles according to  claim 4 , wherein
 the particle growth step starts after part of the liquid component of the aqueous solution for particle growth has been removed.   
     
     
         6 . The manufacturing method for manufacturing nickel manganese composite hydroxide particles according to  claim 1 , wherein
 the nickel composite hydroxide that was obtained in the particle growth step is covered with a compound containing the one or more added elements.   
     
     
         7 . Nickel manganese composite hydroxide particles that are expressed by the general formula Ni x Mn y Co z M t (OH) 2+a  (where x+y+z+t=1, 0.3≦x—0.7, 0.1≦y≦0.55, 0≦z≦0.4, 0≦t≦0.1, 0≦a≦0.5, and M is one or more added element that is selected from among Mg, Ca, Al, Ti, V, Cr, Zr, Nb, Mo and W), and that are spherical shaped secondary particles that are formed by a plurality of aggregate primary particles, wherein the secondary particles have an average particle size of 3 to 7 μm, a value [(d90−d10)/average particle size], which is an index indicating the extent of the particle size distribution, of 0.55 or less, the particles having a center section comprising fine primary particles, and an outer shell section on the outside of the center section comprising plate shaped or needle shaped primary particles that are larger than the fine primary particles, with the thickness of the outer shell section being 0.3 to 3 μm. 
     
     
         8 . The nickel manganese composite hydroxide particles according to  claim 7 , wherein
 the fine primary particles have an average particle size of 0.01 to 0.3 μm, and   the plate shaped or needle shaped primary particles that are larger than the fine primary particles have an average particle size of 0.3 to 3 μm.   
     
     
         9 . The nickel manganese composite hydroxide particles according to  claim 7 , wherein
 the ratio of the thickness of the outer shell section with respect to the particle size of the secondary particles is 10 to 45%.   
     
     
         10 . The nickel manganese composite hydroxide particles according to  claim 7 , wherein
 the one or more added elements are uniformly distributed inside the secondary particles and/or uniformly cover the surface of the secondary particles.   
     
     
         11 . (canceled) 
     
     
         12 . A manufacturing method for manufacturing cathode active material for a non-aqueous electrolyte secondary battery comprising lithium nickel manganese composite oxide having layered hexagonal crystal structure and expressed by the general formula: Li 1+u Ni x Mn y Co z M t O 2  (where −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),
 the manufacturing method comprising: 
 a mixing step that mixes a lithium compound into the nickel manganese composite hydroxide particles of  claim 7  to form a lithium mixture; and 
 a calcination step that performs calcination of the mixture formed in the mixing step in an oxygen atmosphere at a temperature of 800 to 980° C. 
 
     
     
         13 . The manufacturing method for manufacturing cathode active material for a non-aqueous electrolyte secondary battery according to  claim 12 , wherein
 the lithium mixture is adjusted so that the ratio of the sum of the number of metal atoms other than lithium included in the lithium mixture and the number of lithium atoms is 1:0.95 to 1.5.   
     
     
         14 . The manufacturing method for manufacturing cathode active material for a non-aqueous electrolyte secondary battery according to  claim 12 , wherein
 in the mixing step, the nickel manganese composite hydroxide particles have already been heat treated before mixing at a temperature of 105 to 750° C.   
     
     
         15 . The manufacturing method for manufacturing cathode active material for a non-aqueous electrolyte secondary battery according to  claim 12 , wherein
 in the calcination step, temporary calcination has already been performed before calcination at a temperature of 350 to 800° C.   
     
     
         16 . The manufacturing method for manufacturing cathode active material for a non-aqueous electrolyte secondary battery according to  claim 12 , wherein
 the oxygen atmosphere during the calcination step is an atmosphere having an oxygen content of 18 to 100% by volume.   
     
     
         17 . A cathode active material for a non-aqueous electrolyte secondary battery that is expressed by the general formula: Li 1+u Ni x Mn y Co z M t O 2  (where −0.05≦x≦0.50,x+y+z+t=1, 0.3≦x≦0.7, 0.1≦y≦0.55, 0≦x≦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), and comprises lithium nickel manganese composite oxide that is formed from a layered hexagonal crystalline lithium containing composite oxide having an average particle size of 2 to 8 μm, a value [(d90−d10)/average particle size], which is an index indicating the extent of the particle size distribution, of 0.60 or less, a specific surface area of 1 to 2 m 2 /g, and having a hollow structure comprising a hollow section inside the particles and an outer shell section on the outside, with the thickness of the outer shell section being 0.5 to 2.5 μm. 
     
     
         18 . The cathode active material for a non-aqueous electrolyte secondary battery according to  claim 17 , wherein the ratio of the thickness of the outer shell section with respect to the particle size of the lithium nickel manganese composite oxide particles is 5 to 45%. 
     
     
         19 . (canceled) 
     
     
         20 . A non-aqueous electrolyte secondary battery, the cathode thereof being formed using the cathode active material for a non-aqueous electrolyte secondary battery according to  claim 17 .