Positive electrode active material for non-aqueous electrolyte secondary battery, process for preparing the same, and positive electrode for non-aqueous electrolyte secondary battery and non-aqueous electrolyte secondary battery

1. A positive electrode active material for non-aqueous electrolyte secondary battery,

wherein oxide containing Al and/or hydroxide containing Al having protruding-shape is uniformly distributed and adhered to the surface of a positive electrode active material particle;

wherein said oxide containing Al and/or hydroxide containing Al being made to have a protruding-shape after being adhered to the surface of the positive electrode active material;

wherein an adherent amount of oxide containing Al and/or hydroxide containing Al with respect to the positive electrode active material particle is 0.03 mass % or more;

wherein said oxide containing Al and/or hydroxide containing Al having the protruding-shape is formed in fibrous and/or flat plate; and

wherein the protruding-shape formed in fibrous and/or flat plate is adhered vertically on the surface of positive electrode active material particle.

2. The positive electrode active material for non-aqueous electrolyte secondary battery as claimed in claim 1 ,

wherein a material which is uniformly distributed and adhered to the surface of the positive electrode active material particle is oxide containing Al having the protruding-shape.

3. The positive electrode active material for non-aqueous electrolyte secondary battery according to claim 1 ,

wherein phosphoric acid composite is also adhered to the surface of the positive electrode active material particle.

4. The positive electrode active material for non-aqueous electrolyte secondary battery according to claim 1 ,

wherein phosphoric acid composite is trilithium phosphate.

5. A process for preparing a positive electrode active material for non-aqueous electrolyte secondary battery comprising the steps of:

depositing hydroxide containing Al on the surface of a positive electrode active material particle in an aqueous solution dissolving Al salt;

and heat-treating the positive electrode active material particle on which hydroxide containing Al is deposited.

6. The process for preparing the positive electrode active material for non-aqueous electrolyte secondary battery as claimed in claim 5 ,

wherein pH of the aqueous solution dissolving Al salt is adjusted to be within the range of 7 to 11 in the case of deposition of hydroxide containing Al on the surface of the positive electrode active material particle.

7. The process for preparing the positive electrode active material for non-aqueous electrolyte secondary battery as claimed in claim 5 ,

wherein the pH of the aqueous solution dissolving Al salt is adjusted to be within the range of 7 to 9 in the case of deposition of hydroxide containing Al on the surface of the positive electrode active material particle.

8. The process for preparing the positive electrode active material for non-aqueous electrolyte secondary battery as claimed in claim 5 ,

wherein temperature of heat-treating the positive electrode active material particle on which hydroxide containing Al is deposited is 200° C. or more.

9. A positive electrode for non-aqueous electrolyte secondary battery,

wherein the positive electrode active material for non-aqueous electrolyte secondary battery according to claim 1 is employed as a positive electrode active material.

10. A non-aqueous electrolyte secondary battery comprising a positive electrode, a negative electrode, and a non-aqueous electrolyte, wherein the positive electrode for non-aqueous electrolyte secondary battery according to claim 9 is utilized as the positive electrode.

11. The non-aqueous electrolyte secondary battery as claimed in claim 10 , wherein the positive electrode is charged to 4.40 V or more with respect to lithium metal.

12. The non-aqueous electrolyte secondary battery as claimed in claim 10 , wherein the positive electrode is charged to 4.43 V or more with respect to lithium metal.

13. The non-aqueous electrolyte secondary battery as claimed in claim 10 , wherein the positive electrode is charged to 4.47 V or more with respect to lithium metal.

14. The non-aqueous electrolyte secondary battery as claimed in claim 10 which may be used under environments of 50° C. or more.