Disclosed herein is an electrode assembly configured to have a structure in which a bi-cell and two or more monocells are folded in a state in which the bi-cell and the two or more monocells are arranged on a continuous separation film. The bi-cell includes electrodes in the form of at least one cathode and at least one anode stacked so that a separator is disposed between the cathode and the anode, the bi-cell having a first dimension in a first direction substantially equal to w. The two or more monocells each include electrodes in the form of at least one cathode and at least one anode stacked so that a separator is disposed between the cathode and the anode, each cathode and each anode of each monocell having a first dimension in the first direction substantially equal to 2 times the first dimension w of the bi-cell.