Cathode based upon two kinds of compounds and lithium secondary battery comprising the same
View Patent ↗Provided is a cathode for lithium secondary batteries comprising a combination of one or more compounds selected from Formula 1 and one or more compounds selected from Formula 2. The cathode provides a high power lithium secondary battery composed of a non-aqueous electrolyte which exhibits long lifespan, long-period storage properties and superior stability at ambient temperature and high temperatures.
1. A cathode for lithium secondary batteries comprising a mixture of one or more compounds selected from Formula 1 and one or more compounds selected from Formula 2:
(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)
Li(Li b Mn (2-b-c) M c )O 4 (2)
wherein 0<a<0.3, 0<x<0.8; 0<y<0.6; 0<s<0.05, 0<t<0.05, 0<b<0.3 and 0c≦0.2, M is aluminum.
2. The cathode according to claim 1 , wherein a mix ratio of the compound of Formula 1 to the compound of Formula 2 is 1:9 to 9:1, on a weight basis.
3. The cathode according to claim 1 , wherein a mix ratio of the compound of Formula 1 to the compound of Formula 2 is 2:8 to 8:2, on a weight basis.
4. A lithium secondary battery comprising the cathode according to claim 1 .
5. The lithium secondary battery according to claim 4 , wherein the secondary battery is used as a unit battery of a battery module being a power source of medium and large devices.
6. A lithium secondary battery comprising the cathode according to claim 2 .
7. A lithium secondary battery comprising the cathode according to claim 3 .
8. The lithium secondary battery according to claim 6 , wherein the secondary battery is used as a unit battery of a battery module being a power source of medium and large devices.
9. The lithium secondary battery according to claim 7 , wherein the secondary battery is used as a unit battery of a battery module being a power source of medium and large devices.
10. The cathode according to claim 1 , wherein Li 2 CO 3 and LiOH are present in an amount less than 0.03 moles based on the total moles of the compound of Formula (1).
11. A cathode for lithium secondary batteries comprising a combination of one or more compounds selected from Formula 1 and one or more compounds selected from Formula 2:
(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)
Li(Li b Mn (2-b-c) M c )O 4 (2)
wherein 0<a<0.3, 0<x<0.8; 0<y<0.6; 0<s<0.05, 0<t<0.05, 0<b<0.3 and 0<c≦0.2,
M is aluminum, and
wherein Li 2 CO 3 and LiOH are present in an amount less than 0.05 moles based on the total moles of the compound of Formula (1).