Positive electrode active material for non-aqueous electrolyte secondary battery, non-aqueous electrolyte secondary battery, battery pack, and method for manufacturing positive electrode active material for non-aqueous electrolyte secondary battery
According to one embodiment, it is provided with a positive electrode active material for a non-aqueous electrolyte secondary battery represented by a general formula Li(Li a Mn b Ni c Co d Fe e )O 2-x F x , wherein a, b, c, d, e and x in the general formula are values such that 0<a≦0.33, 0<b≦0.67, 0≦c<1, 0≦d<1, 0≦e<1 and 0.1≦x≦1−b, and the following formula (1) is satisfied: 3 ≤ 3 - x - a - 2 c - 3 d - 3 e b < 4. ( 1 )
1. A positive electrode active material for a non-aqueous electrolyte secondary battery, the positive electrode active material having a formula Li(Li a Mn b Ni c Co d Fe e )O 2-x F x ,
wherein a, b, c, d, e, and x satisfy 0.2≦a≦0.33, 0<b≦0.67, 0≦c<1, 0≦d<1, 0≦e<1, and 0.2≦x≦1−b, and wherein formula (1) is satisfied:
3
≤
3
-
x
-
a
-
2
c
-
3
d
-
3
e
b
<
3.66
.
(
1
)
2. The positive electrode active material of claim 1 , in which 0.4<b≦0.67.
3. The positive electrode active material of claim 1 , in which 0.6<b≦0.67.
4. The positive electrode active material of claim 1 , capable of providing an initial coulombic efficiency of at least 75.2%.
5. The positive electrode active material of claim 1 , wherein 0.3≦x≦1−b.
6. The positive electrode active material of claim 1 , wherein 0.2<x≦1−b.
7. A non-aqueous electrolyte secondary battery comprising:
a positive electrode comprising the positive electrode active material of claim 1 ;
a negative electrode comprising a negative electrode active material; and
a non-aqueous electrolyte.
8. The battery of claim 7 further comprising a container formed of a laminate film.
9. A battery pack comprising at least one non-aqueous electrolyte secondary battery according to claim 8 .
10. The battery pack of claim 9 , comprising a plurality of the non-aqueous electrolyte secondary batteries that are electrically connected with each other, and further comprising a protecting circuit capable of detecting a voltage of each of the non-aqueous electrolyte secondary batteries.
11. The battery of claim 7 , further comprising a negative electrode terminal which is electrically connected to the negative electrode and comprises aluminum or an aluminum alloy comprising Mg, Ti, Zn, Mn, Fe, Cu, or Si.
12. The battery of claim 7 , further comprising a positive electrode terminal which is electrically connected to the positive electrode and comprises aluminum or an aluminum alloy comprising Mg, Ti, Zn, Mn, Fe, Cu, or Si.
13. The battery of claim 7 , wherein the negative electrode comprises a negative electrode collector comprising an aluminum foil or an aluminum alloy foil comprising Mg, Ti, Zn, Mn, Fe, Cu, or Si.
14. The battery of claim 7 , wherein the positive electrode comprises a positive electrode collector comprising an aluminum foil or an aluminum alloy foil containing Mg, Ti, Zn, Mn, Fe, Cu, or Si.
15. The battery of claim 7 further comprising a container which is a metal case with a thickness of not more than 1.0 mm.
16. A method for manufacturing the positive electrode active material of claim 1 , the method comprising:
mixing at least a transition metal hydroxide, lithium hydroxide, and ammonium fluoride together, thereby obtaining a mixture and
firing the mixture at a temperature of not less than 700 degrees C. and not more than 1000 degrees C. for not less than five hours and not more than 48 hours.
17. The method of claim 16 , wherein the transition metal hydroxide is synthesized by a coprecipitation method.