Patent ID: 11870068
Assignee: SK ON CO., LTD.
Field: Electrical machinery, apparatus, energy (Electrical engineering)
Classification: CPC H  Y | IPC H

Claim 0:
1. A secondary battery, comprising:
a cathode active material comprising lithium-metal oxide; and
a conductive material mixture in which carbon nanotube is mixed with carbon black,
wherein the carbon black and the carbon nanotube are mixed at a mixing ratio of 4:1 to 2:3,
wherein the cathode active material comprises M1 which has a concentration gradient region in which a concentration is decreased from a central portion up to a surface portion, M2 which has a predetermined concentration from the central portion up to the surface portion, and M3 which has a concentration gradient region in which a concentration is increased from the central portion up to the surface portion,
wherein M1 is Ni, and M2 and M3 are selected from the group consisting of Co and Mn,
wherein a molar ratio of M1 in the cathode active material is XM1, a molar ratio of M2 in the cathode active material is XM2, and a molar ratio of M3 in the cathode active material is XM3, and
wherein XM1:(XM2+XM3) is 7:3 to 9:1.