Lithium—transition metal oxide powder and method of producing the same, positive electrode active material for lithium ion battery, and lithium ion secondary battery
There is provided a lithium-transition metal oxide powder with a coating layer containing lithium niobate formed on a part or the whole part of a surface of a lithium-transition metal oxide particle and having a low powder compact resistance, and a positive electrode active material for a lithium ion battery containing the lithium-transition metal oxide powder. Specifically, there is provided the lithium-transition metal oxide powder composed of a lithium-transition metal oxide particle with a part or the whole part of a surface coated with a coating layer containing lithium niobate, wherein a carbon-content is 0.03 mass % or less.
1. A lithium-transition metal oxide powder composed of a lithium-transition metal oxide particle with a part or the whole part of a surface coated with a coating layer containing lithium niobate, wherein a carbon-content of the lithium-transition metal oxide powder composed of a lithium-transition metal oxide particle with the coating layer 0.03 mass % or less,
a thickness of the coating layer is 100 nm or less, and
a carbon-content of the lithium-transition metal oxide powder with the coating layer of 15 nm average thickness is 0.005-0.013 mass %.
2. The lithium-transition metal oxide powder according to claim 1 , wherein a coating thickness of the coating layer containing the lithium niobate, is 1-50 nm.
3. The lithium-transition metal oxide powder according to claim 1 , wherein the lithium-transition metal oxide is lithium cobaltate.
4. The lithium-transition metal oxide powder according to claim 3 , which powder has a powder compact resistance of 1860-3380Ω·cm when 1 g of said powder is put in a mold with a size of φ20 mm, and a pressure of 12 kN is added thereto, to obtain a powder compact.
5. A positive electrode active material for a lithium ion battery, containing the lithium-transition metal oxide powder of claim 4 .
6. A positive electrode active material for a lithium ion battery, containing the lithium-transition metal oxide powder of claim 3 .
7. The lithium-transition metal oxide powder according to claim 3 , wherein a coating thickness of the coating layer containing the lithium niobate, is from 2 nm to 30 nm.
8. The lithium-transition metal oxide powder according to claim 1 , which powder has a powder compact resistance of 1860-3380Ω·cm when 1 g of said powder is put in a mold with a size of φ20 mm, and a pressure of 12 kN is added thereto, to obtain a powder compact.
9. A positive electrode active material for a lithium ion battery, containing the lithium-transition metal oxide powder of claim 8 .
10. The lithium-transition metal oxide powder according to claim 8 , wherein a coating thickness of the coating layer containing the lithium niobate, is from 2 nm to 30 nm.
11. A positive electrode active material for a lithium ion battery, containing the lithium-transition metal oxide powder of claim 1 .
12. A lithium ion secondary battery, wherein the positive electrode active material for the lithium ion battery of claim 11 is used as a positive electrode active material.
13. The lithium-transition metal oxide powder according to claim 1 , wherein a coating thickness of the coating layer containing the lithium niobate, is from 2 nm to 30 nm.