ENERGY HARVESTING DEVICE

Provided is an energy harvesting device for producing electric power by conduction of alkali ions, including a laminated film in which two-dimensional (2D) materials are laminated and assembled, wherein the laminated film includes a first region into which alkali ions are introduced, a second region into which alkali ions are introduced at a concentration lower than that of the first region or into which alkali ions are not introduced, and a third region located between the first region and the second region to divide the first region and the second region, and in which an interlayer distance between the 2D materials is fixed by physical constraints.