Positive electrode active material for non-aqueous electrolyte secondary cell and cell using the same
There is provided a positive electrode active material for a non-aqueous electrolyte secondary battery, comprising a composite oxide represented by the general formula (1): (Li 1-x M x ) a (Co 1-y M y ) b O c where lithium and cobalt are partly replaced with element M in the crystal structure of LiCoO c , wherein element M is at least one selected from the group consisting of Al, Cu, Zn, Mg, Ca, Ba and Sr, and 0.02≦x+y≦0.15, 0.90≦a/b≦1.10, and 1.8≦c≦2.2 are satisfied.
1. A positive electrode active material for a non-aqueous electrolyte secondary battery, comprising a composite oxide represented by the general formula (1):
(Li 1-x M x ) a (CO 1-y M y ) b O c (1)
where lithium and cobalt are partly replaced with element M in a crystal structure of LiCoO c ,
wherein element M is at least one selected from the group consisting of Al, Cu, Zn, Mg, Ca, Ba and Sr, and
0. 02≦ x+y≦ 0.15,
0.90≦ a/b≦ 1.10,
1.8≦c≦2.2, and
x≠0 and y≠0
are satisfied.
2. The positive electrode active material for a non-aqueous electrolyte secondary battery in accordance with claim 1 , wherein said composite oxide has an α-NaFeO 2 type layer structure belonging to space group R3-m.
3. The positive electrode active material for a non-aqueous electrolyte secondary battery in accordance with claim 1 , wherein said composite oxide has a mean particle diameter of 5 to 20 μm.
4. The positive electrode active material for a non-aqueous electrolyte secondary battery in accordance with claim 1 , wherein said composite oxide has a specific surface area of 0.3 to 1.2 m 2 /g.
5. A non-aqueous electrolyte secondary battery comprising:
a positive electrode comprising the positive electrode active material in accordance with claim 1 ;
a negative electrode comprising metallic lithium or a material capable of absorbing and desorbing lithium; and
a non-aqueous electrolyte.
6. A non-aqueous electrolyte secondary battery comprising:
a positive electrode comprising the positive electrode active material in accordance with claim 2 ;
a negative electrode comprising metallic lithium or a material capable of absorbing and desorbing lithium; and
a non-aqueous electrolyte.
7. A non-aqueous electrolyte secondary battery comprising:
a positive electrode comprising the positive electrode active material in accordance with claim 3 ;
a negative electrode comprising metallic lithium or a material capable of absorbing and desorbing lithium; and
a non-aqueous electrolyte.
8. A non-aqueous electrolyte secondary battery comprising:
a positive electrode comprising the positive electrode active material in accordance with claim 4 ;
a negative electrode comprising metallic lithium or a material capable of absorbing and desorbing lithium; and
a non-aqueous electrolyte.