An electric device has a curved structure formed at at least one position of an outside thereof. At least one secondary battery having an external appearance corresponding to a shape of the curved structure is mounted at the position of the electric device at which the curved structure is formed. The secondary battery is a battery cell having an electrode assembly including a cathode, an anode, and a separator disposed between the cathode and the anode mounted in a battery case or a battery pack having the battery cell mounted in a pack case.