The present invention relates to a high-voltage electric double layer
capacitor (EDLC), and more particularly, to an EDLC in which a surge
voltage and an operating voltage are enhanced by improving the structure
of a unit cell. The EDLC according to the present invention includes a
unit cell having at least three electrodes. According to a preferred
embodiment of the present invention, the unit cell has a structure
constructed by sequentially laminating a first insulating paper layer
with a sheet of insulating paper, a first electrode layer with at least
two electrodes, a second insulating paper layer with a sheet of
insulating paper, and a second electrode layer with at least one
electrode. In accordance with the present invention, the number of
electrode-facing surfaces increases, and a surge voltage and an operating
voltage increase in proportion to the increased number of the
electrode-facing surfaces, resulting in a high energy storage density.
Accordingly, the present invention has advantages in that an EDLC with a
single cell can be applied to products, an EDLC module can be
miniaturized, and there is no need for a protection circuit for
maintaining voltage balance on a unit cell basis upon fabrication of the
module.