Cathode active material and lithium secondary battery comprising the same
View Patent ↗Disclosed is a cathode active material for secondary batteries comprising at least one compound selected from the following formula 1: (1−s−t)[Li(Li a Mn (1−a−x−y) Ni x Co y )O 2 ]*s[Li 2 CO 3 ]*t[LiOH] (1) wherein 0<a<0.2, 0<x<0.9, 0<y<0.5, a+x+y<1, 0<s<0.03, and 0<t<0.03; and a, x and y represent a molar ratio, and a and t represent a weight ratio. The cathode active material has long lifespan at room temperature and high temperatures and provides superior stability, although charge and discharge are repeated at a high current.
1. A cathode active material for secondary batteries consisting of:
a compound of formula (1):
(1 −s−t )[Li(Li a (Mn( 1−x−y )Ni x Co y ) 1−a )O 2 ] *s [Li 2 CO 3 ] *t [LiOH] (1)
wherein 0<a<0.2, 0<x<0.9, 0<y<0.5, a+x+y<1, 0.0010≦s<0.0022, 0.0012≦t<0.0026; 0.0022≦s+t<0.0048 and
a, x and y represent a molar ratio, and s and t represent a weight ratio.
2. The cathode active material according to claim 1 ,
wherein a satisfies the condition of 0.01<a≦0.19.
3. The cathode active material according to claim 1 , wherein x is not lower than 0.02 and is lower than 0.8.
4. The cathode active material according to claim 1 , wherein y is higher than 0 and is not higher than 0.3.
5. A cathode mix for second batteries comprising the cathode active material according to claim 1 .
6. A cathode for lithium secondary batteries in which the cathode mix according to claim 5 is applied to a current collector.
7. A lithium secondary battery comprising the cathode according to claim 6 .
8. A middle- or large-sized battery pack comprising the secondary battery according to claim 7 as a unit battery.
9. An electric vehicle, a hybrid electric vehicle or a plug-in hybrid electric vehicle comprising the middle- or large-sized battery pack of claim 8 .