Disclosed herein is a jelly-roll type electrode assembly (“jelly-roll”) of a cathode/separator/anode structure, wherein the jelly-roll is constructed in a structure in which each electrode has active material layers formed on opposite major surfaces of a sheet-type current collector, the loading amount of an active material for the inner active material layer, constituting the inner surface of each sheet when each sheet is wound, is less than that of an active material for the outer active material layer, constituting the outer surface of each sheet when each sheet is wound, and the loading amount of the active material for the inner active material layer gradually increases from the central region of each wound sheet to the outermost region of each wound sheet.