Provided are electrochemical (e.g., double layer capacitor) cell designs,
and methods of their manufacture, which reduce both cell size and
impedance while maintaining inter-electrode dielectric integrity and cell
performance and facilitating manufacturing. The designs adapt
mircofabrication techniques from the field of semiconductor fabrication in
order to form and pattern thin dielectric films on electrodes. Existing
microfabrication techniques allow for the formation of dielectric (e.g.,
polyimide) films having a thickness of about 1 to 2 microns. Dielectric
films formed on electrodes may be patterned according to well known
procedures in the semiconductor fabrication field to provide area for
unimpeded ion exchange between the electrodes. The patterning may produce
contiguous or noncontiguous dielectric layers between the electrodes
having porosity of about 30 to 80%, preferably about 60 to 80% while
dielectric integrity is maintained. The result is a lower impedance,
higher performance, easily fabricated double layer capacitor cell.
