The present invention provides an electrode assembly in which a negative electrode coated with a negative electrode active material on a surface of a negative electrode collector, a separator, and a positive electrode coated with a positive electrode active material on a surface of a positive electrode collector are repeatedly laminated, the electrode assembly comprising: monocells in which the positive electrode, the separator, the negative electrode, and the separator are laminated, wherein at least two or more monocells are laminated, wherein, in any one of the monocells, an expansion part extending lengthily to one side is formed on the separators, and the expansion part of the separator surrounds the monocells laminated to be disposed at the outermost layers to fix the laminated monocells.
Furthermore, the present invention provides an electrode assembly in which a negative electrode coated with a negative electrode active material on a surface of a negative electrode collector, a separator, and a positive electrode coated with a positive electrode active material on a surface of a positive electrode collector are repeatedly laminated, the electrode assembly comprising: monocells in which the positive electrode, the separator, the negative electrode, and the separator are sequentially laminated, wherein at least two or more monocells are laminated, wherein each of the two or more monocells of the monocells comprises a positive electrode extension part, in which a positive electrode collector extends lengthily to one side, and a negative electrode extension part, in which a negative electrode collector extends lengthily to the other side, and the positive electrode extension part and the negative electrode extension part are respectively bonded to a positive electrode extension part and a negative electrode extension part to fix the laminated monocells.