# US 12,759,909 B2 · Faradic porosity cell > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,759,909 B2 - Document ID: US12759909B2 - Status: Granted - Kind: B2 - Application number: 17/932,488 - Filed: 2022-09-15 - Published: 2023-02-02 - Granted: 2026-10-13 - Earliest claimed: 2017-05-18 - Assignees: PowerTech Water, Inc. - Applicants: PowerTech Water, Inc. - Inventors: Lindsay Boehme; Cameron Lippert; James Richardson Landon; Alan Rassoolkhani; Jeffrey Rentschler - Web page: https://patentgrep.com/patent/US12759909B2 ## CPC - C02F 1/4691: {Capacitive deionisation} - B01D 61/428: {Membrane capacitive deionization} - C02F 1/46109: {Electrodes} - C02F 2001/46161: {Porous electrodes} - C02F 2101/22: Chromium or chromium compounds, e.g. chromates - C02F: TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE (separation in general B01D; special arrangements on waterborne vessels of installations for treating water, waste water or sewage, e.g. for producing fresh water, B63J; adding materials to water to prevent corrosion C23F; treating radioactively-contaminated liquids G21F9/04; regeneration of reactants for recirculation into processes, see the relevant places for the processes) - B01D: SEPARATION (separating solids from solids by wet methods B03B, B03D; by pneumatic jigs or tables B03B; by other dry methods B07; magnetic or electrostatic separation of solid materials from solid materials or fluids, separation by high-voltage electric fields B03C; centrifuges, vortex apparatus B04; presses per se for squeezing-out liquid from liquid-containing material B30B9/02; treatment of water C02F, e.g. softening by ion-exchange C02F1/42; {arrangements of air intake cleaners in gas turbine plants F02C7/05} ; arrangements or mounting of filters in air-conditioning, air-humidification or ventilation F24F13/28) ## Abstract An electrochemical device for removing or reducing a target ionic species from an aqueous solution using faradic immobilization includes a first electrode and a second electrode with different void fraction and surface area properties. During operation, due to differences in void fraction (also referred to as void ratio) of the first and the second electrode, water flows through an electrode with a high porosity, while the aqueous solution does not flow through an electrode with a low porosity. Accordingly, the asymmetry of the electrodes provides a desired voltage distribution across the device, which equates to a different voltage at each electrode, to control the speciation of the target ionic species at the anode and the cathode. ## Claims ### Claim 1 An electrochemical device for at least partially removing or reducing a target ionic species from an aqueous solution, the electrochemical device comprising: a faradic porosity cell including: at least one first electrode including an activated carbon film having a void fraction of about 30 percent to about 65 percent and a surface area of about 1200 square meters per gram to about 1400 square meters per gram; at least one second electrode including a carbon felt having a void fraction of about or greater than 95 percent and a surface area of about 0.1 square meters per gram to about 5 square meters per gram; a current collector in contact with the at least one first electrode; and a current collector in contact with the at least one second electrode, wherein a target ionic species is immobilized onto the at least one first electrode or the at least one second electrode such that the target ionic species is not desorbed into a waste stream without application of an external voltage. ### Claim 2 (depends on 1) The electrochemical device of claim 1, further comprising an ion exchange membrane, wherein the ion exchange membrane is an anion exchange membrane or a cation exchange membrane. ### Claim 3 (depends on 1) The electrochemical device of claim 1, further comprising a membrane disposed on the at least one first electrode or the at least one second electrode, wherein the membrane is in a form of a film, a layer, a sheet, a coating, or a combination thereof. ### Claim 4 (depends on 1) The electrochemical device of claim 1, wherein the current collector comprises graphite, titanium, stainless steel, aluminum, copper, nickel, or a combination thereof. ### Claim 5 (depends on 1) The electrochemical device of claim 1, wherein the current collector is in a form of a film, a layer, a metal sheet, a foil sheet, a mesh sheet, or a combination thereof. ### Claim 6 (depends on 1) The electrochemical device of claim 1, wherein the electrochemical device further comprises a separator arranged between the at least one first electrode and the at least one second electrode. ### Claim 7 (depends on 6) The electrochemical device of claim 6, wherein the separator comprises a dielectric material. ### Claim 8 (depends on 7) The electrochemical device of claim 7, wherein the dielectric material comprises a cellulosic material, a silica containing material, or a combination thereof. ### Claim 9 (depends on 1) The electrochemical device of claim 1, wherein the activated carbon film of the at least one first electrode is microporous. ### Claim 10 (depends on 1) The electrochemical device of claim 1, wherein the activated carbon film of the at least one first electrode comprises a binder. ### Claim 11 (depends on 10) The electrochemical device of claim 10, wherein the binder comprises polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), sodium alginate, sodium-carboxymethyl cellulose, an ion exchange binder, or a combination thereof. ### Claim 12 (depends on 1) The electrochemical device of claim 1, wherein the at least one first electrode is a cathode. ### Claim 13 (depends on 1) The electrochemical device of claim 1, wherein the at least one first electrode is an anode. ### Claim 14 (depends on 1) The electrochemical device of claim 1, wherein the at least one second electrode is a cathode. ### Claim 15 (depends on 1) The electrochemical device of claim 1, wherein the at least one second electrode is an anode. ### Claim 16 (depends on 1) The electrochemical device of claim 1, wherein the aqueous solution flows through the at least one second electrode. ### Claim 17 (depends on 1) The electrochemical device of claim 1, wherein the electrochemical device is a stacked device comprising a plurality of the at least one first electrode and a plurality of the at least one second electrode. ### Claim 18 (depends on 1) The electrochemical device of claim 1, wherein the target ionic species is silver, copper, chromium, lead, manganese, nickel, zinc, chlorine, chloramine, or any combination thereof. ### Claim 19 (depends on 18) The electrochemical device of claim 18, wherein the chromium is Cr (VI) and is reduced to Cr (Ill). ### Claim 20 An electrochemical device for at least partially removing or reducing a target ionic species from an aqueous solution, the electrochemical device comprising: a faradic porosity cell including: at least one first electrode comprising a carbon felt having a void fraction of about or greater than 95 percent and a surface area of about 0.1 square meters per gram to about 5 square meters per gram; at least one second electrode comprising a carbonaceous material having a void fraction of about 65 percent to about 99.9 percent and a surface area of about 700 square meters per gram to about 2300 square meters per gram; a current collector in contact with the at least one first electrode; and a current collector in contact with the at least one second electrode, wherein a target ionic species is immobilized on the at least one first electrode or the at least one second electrode such that the target ionic species is not desorbed into a waste stream without application of an external voltage. ### Claim 21 (depends on 20) The electrochemical device of claim 20, further comprising an ion exchange membrane, wherein the ion exchange membrane is an anion exchange membrane or a cation exchange membrane. ### Claim 22 (depends on 20) The electrochemical device of claim 20, further comprising a membrane disposed on the at least one first electrode or the at least one second electrode, wherein the membrane is in a form of a film, a layer, a sheet, a coating, or a combination thereof. ### Claim 23 (depends on 20) The electrochemical device of claim 20, wherein the current collector comprises graphite, titanium, stainless steel, aluminum, copper, nickel, or a combination thereof. ### Claim 24 (depends on 20) The electrochemical device of claim 20, wherein the current collector is in a form of a film, a layer, a metal sheet, a foil sheet, a mesh sheet, or a combination thereof. ### Claim 25 (depends on 20) The electrochemical device of claim 20, wherein the electrochemical device further comprises a separator arranged between the at least one first electrode and the at least one second electrode. ### Claim 26 (depends on 25) The electrochemical device of claim 25, wherein the separator comprises a dielectric material. ### Claim 27 (depends on 26) The electrochemical device of claim 26, wherein the dielectric material comprises a cellulosic material, a silica containing material, or a combination thereof. ### Claim 28 (depends on 20) The electrochemical device of claim 20, wherein the carbonaceous material of the at least one second electrode is a woven cloth. ### Claim 29 (depends on 20) The electrochemical device of claim 20, wherein the carbonaceous material of the at least one second electrode is an activated carbon nonwoven felt. ### Claim 30 (depends on 20) The electrochemical device of claim 20, wherein the at least one first electrode is a cathode. ### Claim 31 (depends on 20) The electrochemical device of claim 20, wherein the at least one first electrode is an anode. ### Claim 32 (depends on 20) The electrochemical device of claim 20, wherein the at least one second electrode is a cathode. ### Claim 33 (depends on 20) The electrochemical device of claim 20, wherein the at least one second electrode is an anode. ### Claim 34 (depends on 20) The electrochemical device of claim 20, wherein the aqueous solution flows through the at least one second electrode. ### Claim 35 (depends on 20) The electrochemical device of claim 20, wherein the electrochemical device is a stacked device comprising a plurality of the at least one first electrode and a plurality of the at least one second electrode. ### Claim 36 (depends on 20) The electrochemical device of claim 20, wherein the target ionic species is silver, copper, chromium, lead, manganese, nickel, zinc, chlorine, chloramine, or any combination thereof. ### Claim 37 (depends on 36) The electrochemical device of claim 36, wherein the chromium is Cr (VI) and is reduced to Cr (Ill).