  Supercapacitors (aka electrostatic double-layer capacitors -- EDLCs) offer
excellent power storage capacity and kinetics, but suffer under rapid
self-discharge. We introduced a zeolite framework into the active capacitor
electrode, with the goal to tailor the free desorption energy and thus the
self-discharge rate of supercapacitors. Low-cost carbonaceous materials and
benchtop production methods were used to create supercapacitor electrodes with
a measured specific capacitance of 17.25 F g$^{-1}$, a coulombic efficiency of
100%, and charge retention of over 25% over 24 hours determined by
galvanostatic charge/discharge curve measurements. This charge retention was an
enhancement of $\sim$350% compared with electrodes without zeolite coating.
