Method of making a charge barrier capacitor electrode
Flow-through capacitors are provided with one or more charge barrier layers. Ions trapped in the pore volume of flow-through capacitors cause inefficiencies as these ions are expelled during the charge cycle into the purification path. A charge barrier layer holds these pore volume ions to one side of a desired flow stream, thereby increasing the efficiency with which the flow-through capacitor purifies or concentrates ions.
1 . A method of making a capacitor electrode layer, comprising:
(a) forming a mixture comprising activated carbon particles, a binder, a plasticizer, and a conductive material selected from the group consisting of conductive ceramic, conductive aerogel, carbon black, carbon fibers and carbon nanotubes;
(b) including in said mixture a charge barrier material comprising an ion exchange material; and
(c) calendaring said mixture to form said capacitor electrode layer, said capacitor electrode characterized in that said charge barrier material is evenly distributed throughout said capacitor electrode layer.
2 . The method of claim 1 , further comprising making a capacitor electrode by combining one or more of said capacitor electrode layers.