# US 7,833,400 B2 · Method of making a flow through capacitor > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,833,400 B2 - Document ID: US7833400B2 - Status: Granted - Kind: B2 - Application number: 11/007,566 - Filed: 2004-12-08 - Published: 2005-05-19 - Granted: 2010-11-16 - Earliest claimed: 2001-04-18 - Assignees: Biosource, Inc. - Inventors: Marc D. Andelman; Gregory S. Walker - Web page: https://patentgrep.com/patent/US7833400B2 ## CPC - C02F 1/4695: {electrodeionisation} - C02F 1/008: {Control or steering systems not provided for elsewhere in subclass C02F} - C02F 1/4691: {Capacitive deionisation} - C02F 1/469: by electrochemical separation, e.g. by electro-osmosis, electrodialysis, electrophoresis - C02F 2103/08: Seawater, e.g. for desalination - C02F 2201/005: Valves - C02F 2201/46: Apparatus for electrochemical processes - C02F 2201/46145: Fluid flow - C02F 2209/001: Upstream control, i.e. monitoring for predictive control - C02F 2209/003: Downstream control, i.e. outlet monitoring, e.g. to check the treating agents, such as halogens or ozone, leaving the process - C02F 2209/005: Processes using a programmable logic controller [PLC] - C02F 2209/05: Conductivity or salinity - 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) ## Abstract 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. ## Claims ### Claim 1 A method of making a flow-through capacitor, said method comprising: providing a plurality of electrodes comprising an electrode material having an electrostatic adsorptive surface area, wherein at least one of said electrodes comprises a plurality of pores whereby said at least one electrode is a porous electrode having a pore volume; locating a first membrane, material of the first membrane being different from said electrode material and the first membrane being other than a spacer, adjacent to said porous electrode; and positioning a spacer adjacent the first membrane, the spacer defining a flow path. ### Claim 2 (depends on 1) The method of claim 1, wherein said pores are holes in said porous electrode. ### Claim 3 (depends on 2) The method of claim 2, wherein said holes are through holes. ### Claim 4 (depends on 2) The method of claim 2, wherein said holes are honeycomb holes. ### Claim 5 (depends on 1) The method of claim 1, wherein the first membrane comprises a first semipermeable membrane. ### Claim 6 (depends on 5) The method of claim 5, wherein said method further comprises locating a second membrane, material of the second membrane being different from said electrode material, adjacent a second porous electrode of said electrodes, wherein said second membrane comprises a second semipermeable membrane, said first membrane being a cation exchange membrane and said second membrane being an anion exchange membrane. ### Claim 7 (depends on 6) The method of claim 6, wherein the anion exchange membrane is located proximal to an anode, and the cation exchange membrane is located proximal to a cathode. ### Claim 8 (depends on 7) The method of claim 7, wherein at least one of the electrodes is an anode and at least one of the electrodes is a cathode, and wherein the locations of the anion and cation exchange membranes relative to the electrodes are reversed by reversal of voltage polarity on the electrodes. ### Claim 9 (depends on 5) The method of claim 5, further comprising locating a second membrane, material of the second membrane being different from said electrode material, adjacent a second porous electrode of said electrodes, wherein said first and second membranes are identically-charged semipermeable membranes selected from the group consisting of cation exchange membranes and anion exchange membranes. ### Claim 10 (depends on 1) The method of claim 1, further comprising positioning a flow channel in fluid communication with at least one of said electrodes. ### Claim 11 (depends on 10) The method of claim 10, comprising using a spacer to form said flow channel. ### Claim 12 (depends on 10) The method of claim 10, wherein said positioning comprises locating the flow channel between one of the electrodes and the first membrane. ### Claim 13 (depends on 10) The method of claim 10, wherein said method further comprises locating a second membrane, material of the second membrane being different from said electrode material, adjacent a second porous electrode of said electrodes, and positioning a second flow channel between the first and second membranes. ### Claim 14 (depends on 1) The method of claim 1, further comprising applying a voltage to said first membrane and applying a voltage to one or more electrodes of said plurality of electrodes, the first membrane voltage being greater than the electrode voltage. ### Claim 15 (depends on 1) The method of claim 1, wherein the flow-through capacitor comprises a series resistance of less than 50 ohm cm2. ### Claim 16 (depends on 1) The method of claim 1, wherein the flow-through capacitor has a leakage resistance to series resistance ratio of greater than 100. ### Claim 17 (depends on 1) The method of claim 1, wherein the electrodes within a cell of the capacitor are ionically insulated and connected electrically in series. ### Claim 18 (depends on 17) The method of claim 17, further comprising positioning a flow channel in fluid communication with each of said electrodes. ### Claim 19 (depends on 1) The method of claim 1, wherein said first membrane is electrically connected to a first power supply, and at least one of the plurality of electrodes is electrically connected to a second power supply. ### Claim 20 (depends on 1) The method of claim 1, wherein locating said first membrane adjacent to said porous electrode comprises applying a laminate coating to the electrode material. ### Claim 21 (depends on 1) The method of claim 1, wherein locating said first membrane adjacent to said porous electrode comprises locating a conductive polymer sheet material in proximity with said porous electrode. ### Claim 22 (depends on 1) The method of claim 1, wherein said first membrane is made from a material selected from the group consisting of a fibrous material, a woven material, and a mesh material. ### Claim 23 (depends on 1) The method of claim 1, wherein said first membrane is an aerogel. ### Claim 24 (depends on 1) The method of claim 1, wherein said first membrane is a hydrogel. ### Claim 25 (depends on 1) The method of claim 1, wherein said first membrane is made from a material selected from the group consisting of a carbon powder material and a graphite material. ### Claim 26 (depends on 1) The method of claim 1, wherein locating said first membrane comprises allowing said first membrane to infiltrate at least a portion of said pore volume of said porous electrode to form a combined electrode membrane composite. ### Claim 27 (depends on 1) The method of claim 1, wherein said flow-through capacitor system comprises a plurality of ion-depleting and ion-concentrating compartments. ### Claim 28 (depends on 1) The method of claim 1, wherein said first membrane comprises an ion-exchange resin. ### Claim 29 (depends on 1) The method of claim 1, wherein said first membrane Comprises one or more bipolar membranes. ### Claim 30 (depends on 1) The method of claim 1, wherein locating said first membrane adjacent said porous electrode comprises placing said first membrane within the pore structure of the electrode. ### Claim 31 (depends on 1) The method of claim 1, wherein said first membrane is infiltrated into the pore structure of the porous electrode. ### Claim 32 (depends on 1) The method of claim 1, wherein locating said first membrane adjacent said porous electrode comprises applying a coating layer to said porous electrode. ### Claim 33 (depends on 1) The method of claim 1, wherein said first membrane has a porosity of less than 10%. ### Claim 34 (depends on 1) The method or claim 1, wherein said first membrane has an ion exchange capacity of over 0.01 milliequivalents per gram. ### Claim 35 (depends on 34) The method of claim 34, wherein d first membrane is selected from the group consisting of an ion exchange polymer and a hydrogel, and locating said first membrane adjacent said porous electrode comprises infiltrating said first membrane into the pore structure of said porous electrode. ### Claim 36 (depends on 34) The method of claim 34, wherein said First membrane is a coating selected from the group consisting of an ion exchange polymer and a hydrogel, and wherein said method further comprises allowing said coating to block the pore volume of said porous electrode. ### Claim 37 (depends on 1) The method of claim 1, wherein said pore volume contains pore ions and said porous electrode has a ratio of feed ions to pore ions, said method further comprising allowing said first membrane to increase the ratio of feed ions to pore ions in said porous electrode. ### Claim 38 (depends on 1) The method of claim 1, wherein at least one of said plurality of electrodes is a double-sided electrode. ### Claim 39 (depends on 38) The method of claim 38, wherein said method further comprises providing a current collector in electrical communication with said porous electrode. ### Claim 40 (depends on 1) The method of claim 1, wherein said flow-capacitor has an ionic efficiency of at least 30%. ### Claim 41 (depends on 1) The method of claim 1, wherein said flow-through capacitor has an ionic efficiency of at least 70%. ### Claim 42 (depends on 1) The method of claim 1, wherein said flow-through capacitor has an energy usage of less than 1 joule per coulomb of ionic charge purified. ### Claim 43 (depends on 1) The method of claim 1, wherein said flow-through capacitor has an energy usage of less than 0.5 joule per coulomb of ionic charge purified. ### Claim 44 (depends on 1) The method of claim 1, wherein said flow-through capacitor has an ionic efficiency of greater than 50% in the presence of a feed stream having an ionic concentration of at least 7500 parts per million. ### Claim 45 (depends on 44) The method of claim 44, wherein said feed stream has an ionic concentration of at least 6000 parts per million. ### Claim 46 (depends on 1) The method of claim 1, wherein said flaw-through capacitor further comprises a current collector. ### Claim 47 A method of making a flow-through capacitor cell, said method comprising: providing a plurality of electrodes; locating a membrane between two adjacent electrodes of said plurality of electrodes, wherein the flow-through capacitor comprises a series resistance of less than 50 ohm cm2; and positioning a spacer between the two adjacent electrodes, the spacer defining a flow path. ### Claim 48 (depends on 47) The method of claim 47, wherein said flow-through capacitor comprises a leakage resistance of greater than 1000 ohm cm2. ### Claim 49 A method of making a flow-through capacitor cell, said method comprising: providing a plurality of electrodes; locating a membrane between two adjacent electrodes of said plurality of electrodes, wherein the flow-through capacitor has a leakage resistance to series resistance ratio of greater than 100; and positioning a spacer between the two adjacent electrodes, the spacer defining a flow path. ### Claim 50 A method of making a flow-through capacitor cell, said method comprising: providing a plurality of electrodes; locating a membrane between two adjacent electrodes of said plurality of electrodes, wherein the electrodes are ionically insulated and connected electrically in series; and positioning a spacer between the two adjacent electrodes, the spacer defining a flow path. ### Claim 51 (depends on 50) The method of claim 50, further comprising providing a flow path adjacent to each of the electrodes. ### Claim 52 (depends on 1) A method of making a flow-through capacitor system comprising: providing at least one flow-through capacitor cell made according to the method of claim 1; and placing a feed stream in fluid communication with said flow-through capacitor cell. ### Claim 53 (depends on 52) The method of claim 52, further comprising providing a valve between said feed stream and said cell. ### Claim 54 (depends on 53) The method of claim 53, wherein said valve is a feedback valve. ### Claim 55 (depends on 53) The method of claim 53, wherein said valve is a three-v valve. ### Claim 56 (depends on 55) The method of claim 55, further comprising directing fluid in said system from a first flow-through capacitor cell to a second flow-through capacitor cell in said system. ### Claim 57 (depends on 53) The method of claim 53, further comprising allowing a fluid in said system to bypass a flow-through capacitor cell in said system. ### Claim 58 (depends on 52) The method of claim 52, further comprising placing a fluid outlet stream in fluid communication with said flow-through capacitor cell. ### Claim 59 (depends on 52) The method of claim 52, further comprising providing a conductivity controller in ionic communication with said outlet stream. ### Claim 60 (depends on 52) The system of claim 52, further comprising controlling the concentration of ions in a fluid in said system. ### Claim 61 A method of making a capacitor electrode, comprising: providing a capacitive electrode material comprising pores, whereby said electrode material is a porous electrode material; placing a membrane, material of the membrane being different from said electrode material and the membrane being other than a spacer, adjacent to at least a portion of said pores of said porous electrode; and positioning a spacer adjacent the membrane, the spacer defining a flow path. ### Claim 62 (depends on 61) The method of claim 61, wherein said membrane comprises an ion exchange material. ### Claim 63 (depends on 62) The method of claim 62, wherein placing a membrane adjacent to at least a portion of said pores comprises applying said ion exchange material onto said electrode. ### Claim 64 (depends on 61) The method of claim 61, wherein placing a membrane adjacent to at least a portion of said pores comprises infiltrating membrane material into at least a portion of said pores. ### Claim 65 (depends on 64) The method of claim 64, wherein said pores are holes in said electrode. ### Claim 66 (depends on 61) The method of claim 61, wherein said electrode is a carbon electrode and said pores comprise primary surface area pores and secondary pores. ### Claim 67 (depends on 66) The method of claim 66, wherein placing said membrane adjacent to at least a portion of said pores comprises coating said secondary pores with an exchange material. ### Claim 68 (depends on 66) The method of claim 66, wherein placing said membrane adjacent to at least a portion of said pores comprises infiltrating an ion exchange material into said secondary pores. ### Claim 69 (depends on 61) The method of claim 61, wherein said membrane comprises a porous material. ### Claim 70 (depends on 61) The method of claim 61, wherein said membrane comprises a nonporous material.