Cathode active material for lithium rechargeable battery, manufacturing method thereof and lithium rechargeable battery
A method for manufacturing a cathode active material for a lithium rechargeable battery, including: selecting a first metal compound from a group consisting of a halide, a phosphate, a hydrogen phosphate and a sulfate of Mg or Al; selecting a second metal compound from a group consisting of an oxide, a hydroxide and a carbonate of Mg or Al; combining the first metal compound and the second metal compound to obtain a metal compound, the metal compound containing either Mg or Al atoms; mixing a lithium compound, a transition metal compound and the metal compound to obtain a mixture; and sintering the mixture.
1. A cathode active material for a lithium rechargeable battery comprising a lithium transition metal composite oxide containing Mg or Al atoms,
the lithium transition metal composite oxide is obtained from a mixture of a lithium compound, a transition metal compound and a metal compound,
the metal compound containing Mg or Al atoms,
the metal compound is obtained from a first metal compound and a second metal compound,
wherein the first metal compound is selected from a halide, a phosphate, a hydrogen phosphate, and a sulfate of Mg or Al, and
the second metal compound is selected from an oxide, a hydroxide, and a carbonate of Mg or Al,
wherein Mg or Al atoms are contained in a lithium transition metal oxide, said lithium transition metal oxide being represented by one of the general formulas (1) to (4):
Li x CO 1-y Me y O 2 , wherein Me is a transition metal element selected from Ga, and Zn, x being a number in a range of 0.9 ≦x≦ 1.2, and y being a number in a range of 0 ≦y≦ 0.05; (1)
LiFePO 4 ; (2)
LiNi 0.5 Mn 1.5 O 4 ; and (3)
LiMn 2 O 4 , (4)
and wherein the obtained lithium transition metal composite oxide containing Mg or Al atoms contains a metal oxide of MgO or Al 2 O 3 present on or near the surface of a particle and Mg atoms or Al atoms forming a solid solution with the lithium transition metal composite oxide present inside the particle.
2. The cathode active material for a lithium rechargeable battery according to claim 1 , wherein a content of Mg or Al is from 0.01 to 1.0 weight %.
3. The cathode active material for a lithium rechargeable battery according to claim 1 , wherein an additive amount (MC 2 /MC 1 ) of the second metal compound (MC 2 ) with respect to the first metal compound (MC 1 ) is from 20 to 500 weight %.
4. The cathode active material for a lithium rechargeable battery according to claim 1 , wherein a content of free anions liquated out in water is less than or equal to 5000 ppm.
5. A lithium rechargeable battery comprising the cathode active
material for a lithium rechargeable battery according to claim 1 .
6. A method for manufacturing the cathode active material for a lithium rechargeable battery of claim 1 , comprising:
selecting a first metal compound from a group consisting of a halide, a phosphate, a hydrogen phosphate and a sulfate of Mg or Al;
selecting a second metal compound of the metal from a group consisting of an oxide, a hydroxide and a carbonate of Mg or Al;
combining the first metal compound and the second metal compound to obtain a third metal compound, the third metal compound containing Mg or Al atoms;
mixing a lithium compound, a transition metal compound and the third metal compound to obtain a mixture; and
sintering the mixture.
7. The method for manufacturing a cathode active material for a lithium rechargeable battery according claim 6 , wherein an additive amount (MC 2 /MC 1 ) of the second metal compound (MC 2 ) with respect to the first metal compound (MC 1 ) is from 20 to 500 weight %.
8. A cathode active material for a lithium rechargeable battery comprising a lithium transition metal composite oxide containing Mg or Al atoms,
the lithium transition metal composite oxide is obtained from a mixture of a lithium compound, a transition metal compound and a metal compound,
the metal compound containing Mg or Al atoms,
the metal compound is obtained from a first metal compound and a second metal compound,
wherein the first metal compound is selected from a halide, a phosphate, a hydrogen phosphate, and a sulfate of Mg or Al, and
the second metal compound is selected from an oxide, a hydroxide, and a carbonate of Mg or Al,
wherein Mg or Al atoms are contained in a lithium transition metal oxide, said lithium transition metal oxide being represented by general formula (5):
LiNi 1-x-y Co x Mn y O 2 , with 0 ≦x≦ 1.0 and 0 ≦y≦ 1.0; (5)
and wherein the obtained lithium transition metal composite oxide containing Mg or Al atoms contains a metal oxide of MgO or Al 2 O 3 present on or near the surface of a particle and Mg atoms or Al atoms forming a solid solution with the lithium transition metal composite oxide present inside the particle.
9. The cathode active material for a lithium rechargeable battery according to claim 8 , wherein a content of Mg or Al is from 0.01 to 1.0 weight %.
10. The cathode active material for a lithium rechargeable battery according to claim 8 , wherein an additive amount (MC 2 /MC 1 ) of the second metal compound (MC 2 ) with respect to the first metal compound (MC 1 ) is from 20 to 500 weight %.
11. The cathode active material for a lithium rechargeable battery according to claim 8 , wherein a content of free anions liquated out in water is less than or equal to 5000 ppm.
12. A lithium rechargeable battery comprising the cathode active material for a lithium rechargeable battery according to claim 8 .