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 composition 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( l-a-x-y )Ni x Co y )O 2 ]*s[Li 2 CO 3 ]*t[LiOH] (1)
(1-u)LiFePO 4 *uC (2)
wherein 0<a<0.3, 0<x<0.8; 0<y<0.6, 0<s<0.05; 0<t<0.05 and 0.01<u<0.1;
a binder; and
a conductive material.
2. The cathode composition 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 composition 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 composition 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, a power source devices.
6. The cathode composition according to claim 1 , wherein, in Formula 1, lithium carbonate (Li 2 CO 3 ) and lithium hydroxide (LiOH) are present in an amount of 0.03 mole or less, based on the total moles of the compound of Formula 1.