Spinel type lithium nickel manganese-containing composite oxide
Relating to a 5 V-class spinel type lithium nickel manganese-containing composite oxide having an operating potential of 4.5 V or more with respect to a Li metal reference potential, the present invention proposes a composite oxide being capable of improving cycle properties while suppressing the amount of gas generation under high temperature environments and of increasing thermodynamical stability of a positive electrode in a fully charged state. Proposed is a spinel type lithium nickel manganese-containing composite oxide represented by a general formula [Li(Li a Ni y Mn 2-a-b-y-z-α Ti b Al z M α )O 4-σ ] (where 0<a, 0<b, 0.30≤y<0.60, 0<z, 0≤α, 2-a-b-y-z-α<1.7, 3≤b/a≤8, 0.1<b+z+α, 0<z/b≤1, and M represents one or two or more metal elements selected from the group consisting of Mg, Fe, Co, Ba, Cr, W, Mo, Y, Zr, Nb, and Ce).
1. A spinel type lithium nickel manganese-containing composite oxide represented by a general formula [Li(Li a Ni y Mn 2-a-b-y-z-α Ti b Al z M α )O 4-σ ] where 0<a, 0<b, 0.30≤y<0.60, 0<z, 0≤α, 2-a-b-y-z-α<1.7, 3≤b/a≤8, 0.1<b+z+α, 0<z/b≤1, and M represents one or two or more metal elements selected from the group consisting of Mg, Fe, Co, Ba, Cr, W, Mo, Y, Zr, Nb, and Ce.
2. A spinel type lithium nickel manganese-containing composite oxide represented by a general formula [Li(Li a Ni y Mn 2-a-b-y-z-α Ti b Al z M α )O 4-σ ] where 0<a≤0.20, 0.08≤b, 0.30≤y<0.60, 0<z<0.15, 0≤α, 2-a-b-y-z-α<1.7, 3≤b/a≤8, 0.1<b+z+α≤0.3, 0<z/b≤1, and M represents one or two or more metal elements selected from the group consisting of Mg, Fe, Co, Ba, Cr, W, Mo, Y, Zr, Nb, and Ce.
3. The spinel type lithium nickel manganese-containing composite oxide according to claim 1 , wherein α=0 in the above general formula.
4. The spinel type lithium nickel manganese-containing composite oxide according to claim 1 , wherein a molar ratio of Al with respect to a molar ratio of Ni (z/y) in the above general formula is more than 0.01.
5. The spinel type lithium nickel manganese-containing composite oxide according to claim 1 , wherein a molar ratio of Al with respect to a molar ratio of Ti (z/b) in the above general formula is 0<z/b<1.
6. The spinel type lithium nickel manganese-containing composite oxide according to claim 1 , wherein a sulfur impurity content measured by inductively coupled plasma (ICP) emission spectroscopy is less than 0.20 wt %.
7. The spinel type lithium nickel manganese-containing composite oxide according to claim 1 , wherein a Na impurity content is less than 300 ppm.
8. The spinel type lithium nickel manganese-containing composite oxide according to claim 1 , wherein a K impurity content is less than 200 ppm.
9. The spinel type lithium nickel manganese-containing composite oxide according to claim 1 , wherein a Ca impurity content is less than 150 ppm.
10. The spinel type lithium nickel manganese-containing composite oxide according to claim 1 , wherein a specific surface area is 0.1 m 2 /g or more and 2.0 m 2 /g or less.
11. The spinel type lithium nickel manganese-containing composite oxide according to claim 1 , wherein an average particle diameter (D50) determined by a laser diffraction scattering type particle size distribution measurement method is 4 μm or more and 25 μm or less.
12. The spinel type lithium nickel manganese-containing composite oxide according to claim 1 , wherein a tap density is 0.9 g/cm 3 or more.
13. The spinel type lithium nickel manganese-containing composite oxide according to claim 1 , wherein a strain is less than 0.40.
14. A lithium secondary battery having the spinel type lithium nickel manganese-containing composite oxide according to claim 1 as a positive electrode active material.
15. A lithium secondary battery having the spinel type lithium nickel manganese-containing composite oxide according to claim 2 as a positive electrode active material.