An energy storage device can have a first graphite film, a second graphite film and an electrode divider ring between the first graphite film and the second graphite film, forming a sealed enclosure. The energy storage device may be compatible with an aqueous electrolyte or a non-aqueous electrolyte. A method of forming an energy storage device can include providing an electrode divider ring, a first graphite film and a second graphite film. The method can include pressing a first edge of the electrode divider ring into a surface of the first graphite film, and pressing a second opposing edge of the electrode divider ring into a surface of the second graphite film to form a sealed enclosure. The sealed enclosure may have as opposing surfaces the surface of the first graphite film and the surface of the second graphite film.