An electrode assembly comprising a first unit electrode in which a plurality of first electrodes entirely made of a first electrode mixture having a solid shape are connected to each other; a second unit electrode in which a plurality of second electrodes entirely made of a second electrode mixture having a solid shape are connected to each other; a separator interposed between the first unit electrode and the second unit electrode; and an electrode tab comprising a plurality of first electrode tab provided on the first unit electrode and a plurality of second electrode tab provided on the second unit electrode.