Positive electrode active material for lithium secondary battery
Provided is a novel positive electrode active material which can effectively suppress the quantity of gas generated by the reaction with an electrolytic solution. Proposed is a positive electrode active material for a lithium secondary battery including positive electrode active material particles obtained by equipping the entire surface or a part of a surface of lithium manganese-containing composite oxide particles (also referred to as the “core particles”) operating at a charging voltage in a region exceeding 4.3 V in a metal Li reference potential with a layer A containing at least titanium (Ti), aluminum (Al), zirconium (Zr), or two or more kinds of these.
1. A positive electrode active material for a lithium secondary battery comprising positive electrode active material particles, wherein the positive electrode active material particles comprises a layer (referred to as the “layer A”) comprising at least titanium (Ti), aluminum (Al), zirconium (Zr), or two or more kinds of these on a part of a surface of lithium manganese-containing composite oxide particles (also referred to as the “core particles”) operating at a charging voltage in a region exceeding 4.3 V in a metal Li reference potential, wherein a content of carbon (C) in the positive electrode active material is less than 0.1% by mass.
2. The positive electrode active material for a lithium secondary battery according to claim 1 , wherein the layer A further comprises phosphorus (P).
3. The positive electrode active material for a lithium secondary battery according to claim 1 , wherein a thickness of the layer A is from 0.1 to 200 nm.
4. The positive electrode active material for a lithium secondary battery according to claim 1 , wherein the positive electrode active material has a specific surface area of from 0.01 to 3.00 m 2 /g.
5. The positive electrode active material for a lithium secondary battery according to claim 1 , wherein D50 according to a volume-based particle size distribution obtained by measuring by a laser diffraction and scattering particle size distribution measuring method is from 3 to 40 μm.
6. The positive electrode active material for a lithium secondary battery according to claim 1 , wherein D10 according to a volume-based particle size distribution obtained by measuring by a laser diffraction and scattering particle size distribution measuring method is from 1 to 20 μm.
7. The positive electrode active material for a lithium secondary battery according to claim 1 , wherein Dmin according to a volume-based particle size distribution obtained by measuring by a laser diffraction and scattering particle size distribution measuring method is 10 μm or less.
8. The positive electrode active material for a lithium secondary battery according to claim 1 , wherein the lithium manganese-containing composite oxide particles are spinel-type lithium manganese-containing composite oxide particles having an operating potential of 4.5 V or more at a metal Li reference potential.
9. The positive electrode active material for a lithium secondary battery according to claim 1 , wherein the lithium manganese-containing composite oxide particles are spinel-type lithium manganese-containing composite oxide particles including a crystal phase obtained by substituting a part of Mn sites in LiMn 2 O 4-δ with Li, a metal element M1, and another metal element M2.
10. A lithium secondary battery comprising the positive electrode active material for a lithium secondary battery according to claim 1 .
11. A positive electrode active material for a lithium secondary battery comprising positive electrode active material particles, wherein the positive electrode active material particles comprises a layer (referred to as the “layer A”) comprising at least titanium (Ti), aluminum (Al), or both of these on a part of a surface of lithium manganese-containing composite oxide particles (also referred to as the “core particles”) operating at a charging voltage in a region exceeding 4.3 V in a metal Li reference potential, wherein a content of carbon (C) in the positive electrode active material is less than 0.1% by mass.
12. The positive electrode active material for a lithium secondary battery according to claim 11 , wherein the layer A further comprises phosphorus (P).
13. The positive electrode active material for a lithium secondary battery according to claim 11 , wherein a thickness of the layer A is from 0.1 to 200 nm.
14. The positive electrode active material for a lithium secondary battery according to claim 11 , wherein the positive electrode active material has a specific surface area of from 0.01 to 3.00 m 2 /g.
15. The positive electrode active material for a lithium secondary battery according to claim 11 , wherein D50 according to a volume-based particle size distribution obtained by measuring by a laser diffraction and scattering particle size distribution measuring method is from 3 to 40 μm.
16. The positive electrode active material for a lithium secondary battery according to claim 11 , wherein D10 according to a volume-based particle size distribution obtained by measuring by a laser diffraction and scattering particle size distribution measuring method is from 1 to 20 μm.
17. The positive electrode active material for a lithium secondary battery according to claim 11 , wherein Dmin according to a volume-based particle size distribution obtained by measuring by a laser diffraction and scattering particle size distribution measuring method is 10 μm or less.
18. The positive electrode active material for a lithium secondary battery according to claim 11 , wherein the lithium manganese-containing composite oxide particles are spinel-type lithium manganese-containing composite oxide particles having an operating potential of 4.5 V or more at a metal Li reference potential.