Positive electrode active material for non-aqueous electrolyte secondary battery and manufacturing method thereof, and non-aqueous electrolyte secondary battery using same

A positive electrode active material for a non-aqueous electrolyte secondary battery comprising:

• primary particles of a lithium-metal complex oxide powder which is a lithium-metal complex oxide powder represented by LizNi1−x−yTxLyO2, wherein T is at least one metal element selected from the group consisting of Co, and Mn;
• L is at least one metal element selected from the group consisting of Al, Mg, Ti, Fe, Cu, Zn, and Ga;
• and x, y, and z respectively satisfy 0<x<0.25, 0<y≦0.1, 0<x+y≦0.25, and 1.0≦z≦1.1;
• and
• secondary particles which are formed by aggregating a plurality of the primary particles, wherein:
• the shape of the secondary particles is spherical or spheroidal;
• 95% or more of the secondary particles have particle diameters of 20 μm or less;
• a mean particle diameter of the secondary particles is between 7 and 13 μm;
• a tap density of the particles is 2.2 g/cm3 or more;
• in a pore distribution measurement using a nitrogen adsorption method, a mean volume of pores having a diameter of 40 nm or less in average is between 0.001 and 0.008 cm3/g;
• and
• a mean crushing strength of the secondary particles is between 15 and 100 MPa.

A manufacturing method for a positive electrode active material for a non-aqueous electrolyte secondary battery comprising:

• a first step for producing a metal complex hydroxide containing Ni and metal M wherein:
• M is at least one metal element selected from the group consisting of Co, Al, Mg, Mn, Ti, Fe, Cu, Zn, and Ga;
• said metal complex hydroxide has a proportion of Ni:M=1−w:w (0<w≦0.25) in an atomic number ratio;
• and a tap density of 1.7 g/cm3 or more;
• a second step for weighing the metal complex hydroxide obtained in the first step and lithium hydroxide so that a ratio of an atomic number of Li to a total atomic number of Ni and metal M is between 1.0 and 1.1, and mixing to obtain a compound;
• and
• a third step for raising the temperature of the compound obtained in the second step, from room temperature to 450 to 550° C. at a temperature rise rate of 0.5 to 15° C./min, holding for 1 to 10 hours at the reaching temperature, and performing first stage baking, and then further raising the temperature to 650 to 800° C. at a temperature rise rate of 1 to 5° C./min, holding for 0.6 to 30 hours at the reaching temperature, and performing second stage baking, and then furnace cooling to obtain a positive electrode active material for a non-aqueous electrolyte secondary battery.

A manufacturing method for a positive electrode active material for a non-aqueous electrolyte secondary battery comprising:

• a first step for producing a metal complex hydroxide containing Ni and metal T wherein:
• T is at least one metal element selected from the group consisting of Co and Mn;
• and
• said metal complex hydroxide has a proportion of Ni:T=1−x−y:x (0<x<0.25, 0<y≦0.1, and 0<x+y≦0.25) in an atomic number ratio and a tap density of 1.7 g/cm3 or more;
• a second step for adding a compound of a metal L to the metal complex hydroxide obtained in the first step, L being at least one metal element selected from the group consisting of Al, Mg, Ti, Fe, Cu, Zn, and Ga, and mixing, and producing a compound A containing Ni and metal L with a proportion of Ni:L=1−x−y:y(0<x<0.25, 0<y≦0.1, and 0<x+y≦0.25) in an atomic number ratio;
• a third step for weighing the compound A obtained in the second step and lithium hydroxide so that a ratio of an atomic number of Li to a total atomic number of Ni, metal T, and metal L is between 1.0 and 1.1, and mixing to obtain a compound B;
• and
• a fourth step for raising the temperature of the compound B obtained in the third step, from room temperature to 450 to 550° C. at a temperature rise rate of 0.5 to 15° C./min, holding for 1 to 10 hours at the reaching temperature, and performing first stage baking, and then further raising the temperature to 650 to 800° C. at a temperature rise rate of 1 to 5° C./min, holding for 0.6 to 30 hours at the reaching temperature, and performing second stage baking, and then furnace cooling to obtain a positive electrode active material for a non-aqueous electrolyte secondary battery.

A manufacturing method for a positive electrode active material for a non-aqueous electrolyte secondary battery comprising:

• a first step for producing a metal complex hydroxide containing Ni, metal T, and metal L wherein:
• T is at least one kind or more of metal elements selected from the Group consisting of Co and Mn;
• L is at least one kind or more of metal elements selected from the group consisting of Al, Mg, Ti, Fe, Cu, Zn, and Ga;
• and
• said metal complex hydroxide has a proportion of Ni:T:L=1−x−y:x:y (0<x<0.25, 0<y≦0.1, and 0<x+y≦2.5) in an atomic number ratio, and a tap density of 1.7 g/cm3 or more;
• a second step for weighing the metal complex hydroxide obtained in the first step and lithium hydroxide so that a ratio of an atomic number of Li a total atomic number of Ni, metal T, and metal L is between 1.0 and 1.1, and mixing to obtain a compound;
• and
• a third step for raising the temperature of the compound obtained in the second step, from room temperature to 450 to 550° C. at a temperature rise rate of 0.5 to 15° C./min, holding for 1 to 10 hours at the reaching temperature, and performing first stage baking, and then further raising the temperature to 650 to 800° C. at a temperature rise rate of 1 to 5° C./min, holding for 0.6 to 30 hours at the reaching temperature, and performing second stage baking, and then furnace cooling to obtain a positive electrode active material for a non-aqueous electrolyte secondary battery.