Abstract: The present invention relates to the field of lithium-ion battery, and particularly to high-capacity cathode material, and high-energy density lithium-ion secondary battery prepared using the same. The cathode material comprises cathode active material, a binder and a conductive agent, in which the cathode active material is a compound material of lithium cobalt oxide-based active material A and nickel-based active material B pretreated before being mixed, and the mass ratio B/A of the lithium cobalt oxide-based active material A and nickel-based active material B is between 0.82 and 9. The present invention can produce a battery having both larger capacity and higher energy density, and address the problem of gas generation in the battery at high temperature.

Abstract: A cathode electrode for lithium-ion secondary battery includes a current collector; and a cathode material layer comprising a bottom layer coated on the current collector and a top layer coated on the bottom layer. The lithium-ion transfer resistance of the active material particles in the bottom layer is smaller than that of the active material particles in the top layer, optimize the concentration polarization occurred in the cathode electrode during discharge, and enabling the lithium-ion secondary battery using the cathode electrode to be improved both in energy density and safety, and be further enhanced in specific capacity.